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A file format is a standard way that information is encoded for storage in a computer file . It specifies how bits are used to encode information in a digital storage medium. File formats may be either proprietary or free .

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117-393: Qcow is a file format for disk image files used by QEMU , a hosted virtual machine monitor . It stands for "QEMU Copy On Write " and uses a disk storage optimization strategy that delays allocation of storage until it is actually needed. Files in qcow format can contain a variety of disk images which are generally associated with specific guest operating systems . Three versions of

234-469: A decree by which new and inventive devices had to be communicated to the Republic in order to obtain legal protection against potential infringers. The period of protection was 10 years. As Venetians emigrated, they sought similar patent protection in their new homes. This led to the diffusion of patent systems to other countries. The English patent system evolved from its early medieval origins into

351-434: A byte frequency distribution to build the representative models for file type and use any statistical and data mining techniques to identify file types. There are several types of ways to structure data in a file. The most usual ones are described below. Earlier file formats used raw data formats that consisted of directly dumping the memory images of one or more structures into the file. This has several drawbacks. Unless

468-453: A company helping another company to create a patented product or selling the patented product which is created by another company. There is also inducement to infringement, which is when a party induces or assists another party in violating a patent. An example of this would be a company paying another party to create a patented product in order to reduce their competitor's market share. This is important when it comes to gray market goods, which

585-408: A company logo may be needed both in .eps format (for publishing) and .png format (for web sites). With the extensions visible, these would appear as the unique filenames: " CompanyLogo.eps " and " CompanyLogo.png ". On the other hand, hiding the extensions would make both appear as " CompanyLogo ", which can lead to confusion. Hiding extensions can also pose a security risk. For example,

702-520: A few bytes long. The metadata contained in a file header are usually stored at the start of the file, but might be present in other areas too, often including the end, depending on the file format or the type of data contained. Character-based (text) files usually have character-based headers, whereas binary formats usually have binary headers, although this is not a rule. Text-based file headers usually take up more space, but being human-readable, they can easily be examined by using simple software such as

819-448: A file based on the end of its name, more specifically the letters following the final period. This portion of the filename is known as the filename extension . For example, HTML documents are identified by names that end with .html (or .htm ), and GIF images by .gif . In the original FAT file system , file names were limited to an eight-character identifier and a three-character extension, known as an 8.3 filename . There are

936-401: A file format is to use information regarding the format stored inside the file itself, either information meant for this purpose or binary strings that happen to always be in specific locations in files of some formats. Since the easiest place to locate them is at the beginning, such area is usually called a file header when it is greater than a few bytes , or a magic number if it is just

1053-416: A file unusable (or "lose" it) by renaming it incorrectly. This led most versions of Windows and Mac OS to hide the extension when listing files. This prevents the user from accidentally changing the file type, and allows expert users to turn this feature off and display the extensions. Hiding the extension, however, can create the appearance of two or more identical filenames in the same folder. For example,

1170-401: A formal specification document, letting precedent set by other already existing programs that use the format define the format via how these existing programs use it. If the developer of a format does not publish free specifications, another developer looking to utilize that kind of file must either reverse engineer the file to find out how to read it or acquire the specification document from

1287-399: A hierarchical structure, known as a conformance hierarchy. Thus, public.png conforms to a supertype of public.image , which itself conforms to a supertype of public.data . A UTI can exist in multiple hierarchies, which provides great flexibility. In addition to file formats, UTIs can also be used for other entities which can exist in macOS, including: In IBM OS/VS through z/OS ,

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1404-442: A limited number of three-letter extensions, which can cause a given extension to be used by more than one program. Many formats still use three-character extensions even though modern operating systems and application programs no longer have this limitation. Since there is no standard list of extensions, more than one format can use the same extension, which can confuse both the operating system and users. One artifact of this approach

1521-414: A malicious user could create an executable program with an innocent name such as " Holiday photo.jpg.exe ". The " .exe " would be hidden and an unsuspecting user would see " Holiday photo.jpg ", which would appear to be a JPEG image, usually unable to harm the machine. However, the operating system would still see the " .exe " extension and run the program, which would then be able to cause harm to

1638-403: A non-obvious inventive step. A patent is requested by filing a written application at the relevant patent office. The person or company filing the application is referred to as "the applicant". The applicant may be the inventor or its assignee. The application contains a description of how to make and use the invention that must provide sufficient detail for a person skilled in the art (i.e.,

1755-408: A particular file's format, with each approach having its own advantages and disadvantages. Most modern operating systems and individual applications need to use all of the following approaches to read "foreign" file formats, if not work with them completely. One popular method used by many operating systems, including Windows , macOS , CP/M , DOS , VMS , and VM/CMS , is to determine the format of

1872-417: A patent covers or the "scope of protection". After filing, an application is often referred to as " patent pending ". While this term does not confer legal protection, and a patent cannot be enforced until granted, it serves to provide warning to potential infringers that if the patent is issued, they may be liable for damages. Once filed, a patent application is "prosecuted" . A patent examiner reviews

1989-471: A patent. In the United States, however, only the inventor(s) may apply for a patent, although it may be assigned to a corporate entity subsequently and inventors may be required to assign inventions to their employers under an employment contract. In most European countries, ownership of an invention may pass from the inventor to their employer by rule of law if the invention was made in the course of

2106-511: A prohibited act that is protected against by the patent. There is also the Doctrine of Equivalents. This doctrine protects from someone creating a product that is basically, by all rights, the same product that is protected with just a few modifications. In some countries, like the United States, there is liability for another two forms of infringement. One is contributory infringement, which is participating in another's infringement. This could be

2223-400: A right to make or use or sell an invention. Rather, a patent provides, from a legal standpoint, the right to exclude others from making, using, selling, offering for sale, or importing the patented invention for the term of the patent , which is usually 20 years from the filing date subject to the payment of maintenance fees . From an economic and practical standpoint however, a patent

2340-441: A sorted index). Also, data must be read from the file itself, increasing latency as opposed to metadata stored in the directory. Where file types do not lend themselves to recognition in this way, the system must fall back to metadata. It is, however, the best way for a program to check if the file it has been told to process is of the correct format: while the file's name or metadata may be altered independently of its content, failing

2457-431: A specialized editor or IDE . However, this feature was often the source of user confusion, as which program would launch when the files were double-clicked was often unpredictable. RISC OS uses a similar system, consisting of a 12-bit number which can be looked up in a table of descriptions—e.g. the hexadecimal number FF5 is "aliased" to PoScript , representing a PostScript file. A Uniform Type Identifier (UTI)

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2574-485: A text editor or a hexadecimal editor. As well as identifying the file format, file headers may contain metadata about the file and its contents. For example, most image files store information about image format, size, resolution and color space , and optionally authoring information such as who made the image, when and where it was made, what camera model and photographic settings were used ( Exif ), and so on. Such metadata may be used by software reading or interpreting

2691-513: A third party, without authorization from the patentee, makes, uses, or sells a patented invention. Patents, however, are enforced on a national basis. The making of an item in China, for example, that would infringe a US patent, would not constitute infringement under US patent law unless the item were imported into the US. Infringement includes literal infringement of a patent, meaning they are performing

2808-555: A unified procedure for filing patent applications to protect inventions in each of its contracting states along with giving owners a 30-month priority for applications as opposed to the standard 12 the Paris Convention granted. A patent application filed under the PCT is called an international application, or PCT application. The steps for PCT applications are as follows: 1. Filing the PCT patent application 2. Examination during

2925-502: A value in a company/standards organization database), and the 2 following digits categorize the type of file in hexadecimal . The final part is composed of the usual filename extension of the file or the international standard number of the file, padded left with zeros. For example, the PNG file specification has the FFID of 000000001-31-0015948 where 31 indicates an image file, 0015948

3042-638: A way of identifying what type of file was attached to an e-mail , independent of the source and target operating systems. MIME types identify files on BeOS , AmigaOS 4.0 and MorphOS , as well as store unique application signatures for application launching. In AmigaOS and MorphOS, the Mime type system works in parallel with Amiga specific Datatype system. There are problems with the MIME types though; several organizations and people have created their own MIME types without registering them properly with IANA, which makes

3159-428: A well-designed magic number test is a pretty sure sign that the file is either corrupt or of the wrong type. On the other hand, a valid magic number does not guarantee that the file is not corrupt or is of a correct type. So-called shebang lines in script files are a special case of magic numbers. Here, the magic number is human-readable text that identifies a specific command interpreter and options to be passed to

3276-477: A yearly basis. Some countries or regional patent offices (e.g. the European Patent Office ) also require annual renewal fees to be paid for a patent application before it is granted. In the US, patent maintenance fees are due on 3.5, 7.5 and 11.5 anniversaries of the patent issuance. Only ca. 50% of issued US patents are maintained full term. Large corporations tend to pay maintenance fees through

3393-506: Is patentable subject matter from country to country, also among WTO member states. TRIPS also provides that the term of protection available should be a minimum of twenty years. Some countries have other patent-like forms of intellectual property , such as utility models , which have a shorter monopoly period. The word patent originates from the Latin patere , which means "to lay open" (i.e., to make available for public inspection). It

3510-528: Is a method used in macOS for uniquely identifying "typed" classes of entities, such as file formats. It was developed by Apple as a replacement for OSType (type & creator codes). The UTI is a Core Foundation string , which uses a reverse-DNS string. Some common and standard types use a domain called public (e.g. public.png for a Portable Network Graphics image), while other domains can be used for third-party types (e.g. com.adobe.pdf for Portable Document Format ). UTIs can be defined within

3627-407: Is a risk that the file format can be misinterpreted. It may even have been badly written at the source. This can result in corrupt metadata which, in extremely bad cases, might even render the file unreadable. A more complex example of file headers are those used for wrapper (or container) file formats. One way to incorporate file type metadata, often associated with Unix and its derivatives,

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3744-419: Is a shortened version of the term letters patent , which was an open document or instrument issued by a monarch or government granting exclusive rights to a person, predating the modern patent system. Similar grants included land patents , which were land grants by early state governments in the US, and printing patents , a precursor of modern copyright . In modern usage, the term patent usually refers to

3861-454: Is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention. In most countries, patent rights fall under private law and the patent holder must sue someone infringing the patent in order to enforce their rights. The procedure for granting patents, requirements placed on

3978-402: Is added. This allows for smaller file sizes than raw disk images , which allocate the whole image space to a file, even if parts of it are empty. This is particularly useful for file systems that do not support sparse files , such as FAT32 . The qcow format also allows storing changes made to a read-only base image on a separate qcow file by using copy on write . This new qcow file contains

4095-449: Is an extensible scheme of persistent, unique, and unambiguous identifiers for file formats, which has been developed by The National Archives of the UK as part of its PRONOM technical registry service. PUIDs can be expressed as Uniform Resource Identifiers using the info:pronom/ namespace. Although not yet widely used outside of the UK government and some digital preservation programs,

4212-597: Is better and perhaps more precisely regarded as conferring upon its proprietor "a right to try to exclude by asserting the patent in court", for many granted patents turn out to be invalid once their proprietors attempt to assert them in court. A patent is a limited property right the government gives inventors in exchange for their agreement to share details of their inventions with the public. Like any other property right, it may be sold, licensed, mortgaged , assigned or transferred, given away, or simply abandoned. A patent, being an exclusionary right, does not necessarily give

4329-449: Is even more pronounced when the number of patent applications is normalized by the country's population each year, or when the country of origin rather than country of filing is used. For the US, the population-normalized peak in patenting occurred in 1915, and the number of subsequent patents induced per patent has been mostly declining since 1926. A study of 4,512 patents obtained by Stanford University between 1970 and 2020 showed that

4446-726: Is evidence that some form of patent rights was recognized in Ancient Greece in the city of Sybaris , the first statutory patent system is generally regarded to be the Venetian Patent Statute of 1474. However, recent historical research has suggested that the 1474 Statute was inspired by laws in the Kingdom of Jerusalem that granted monopolies to developers of novel silk-making techniques. Patents were systematically granted in Venice as of 1474, where they issued

4563-623: Is patentable. Patentable material must be synthetic, meaning that anything natural cannot be patented. For example, minerals, materials, genes, facts, organisms, and biological processes cannot be patented, but if someone were to apply an inventive, non-obvious, step to them to synthesize something new, the result could be patentable. That includes genetically engineered strains of bacteria, as was decided in Diamond v. Chakrabarty. Patentability also depends on public policy and ethical standards. Additionally, patentable materials must be novel, useful, and

4680-436: Is sent by the patent office, or the patent application is granted, which after the payment of additional fees, leads to an issued, enforceable patent. In some jurisdictions, there are opportunities for third parties to bring an opposition proceeding between grant and issuance, or post-issuance. Once granted the patent is subject in most countries to renewal fees to keep the patent in force. These fees are generally payable on

4797-424: Is small, and/or that chunks do not contain other chunks; many formats do not impose those requirements. The information that identifies a particular "chunk" may be called many different things, often terms including "field name", "identifier", "label", or "tag". The identifiers are often human-readable, and classify parts of the data: for example, as a "surname", "address", "rectangle", "font name", etc. These are not

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4914-427: Is that the system can easily be tricked into treating a file as a different format simply by renaming it — an HTML file can, for instance, be easily treated as plain text by renaming it from filename.html to filename.txt . Although this strategy was useful to expert users who could easily understand and manipulate this information, it was often confusing to less technical users, who could accidentally make

5031-547: Is the Paris Convention for the Protection of Industrial Property , initially signed in 1883. The Paris Convention sets out a range of basic rules relating to patents, and although the convention does not have direct legal effect in all national jurisdictions, the principles of the convention are incorporated into all notable current patent systems. The Paris Convention set a minimum patent protection of 20 years, but

5148-648: Is the standard number and 000000001 indicates the International Organization for Standardization (ISO). Another less popular way to identify the file format is to examine the file contents for distinguishable patterns among file types. The contents of a file are a sequence of bytes and a byte has 256 unique permutations (0–255). Thus, counting the occurrence of byte patterns that is often referred to as byte frequency distribution gives distinguishable patterns to identify file types. There are many content-based file type identification schemes that use

5265-463: Is therefore only useful for protecting an invention in the country in which that patent is granted. In other words, patent law is territorial in nature. When a patent application is published, the invention disclosed in the application becomes prior art and enters the public domain (if not protected by other patents) in countries where a patent applicant does not seek protection, the application thus generally becoming prior art against anyone (including

5382-479: Is to store a "magic number" inside the file itself. Originally, this term was used for a specific set of 2-byte identifiers at the beginnings of files, but since any binary sequence can be regarded as a number, any feature of a file format which uniquely distinguishes it can be used for identification. GIF images, for instance, always begin with the ASCII representation of either GIF87a or GIF89a , depending upon

5499-434: Is when a patent owner sells a product in country A, wherein they have the product patented, then another party buys and sells it, without the owner's permission, in country B, wherein the owner also has a patent for the product. With either national or regional exhaustion being the law the in country B, the owner may still be able to enforce their patent rights; however, if country B has a policy of international exhaustion, then

5616-590: The GIF file format required the use of a patented algorithm, and though the patent owner did not initially enforce their patent, they later began collecting royalty fees . This has resulted in a significant decrease in the use of GIFs, and is partly responsible for the development of the alternative PNG format. However, the GIF patent expired in the US in mid-2003, and worldwide in mid-2004. Different operating systems have traditionally taken different approaches to determining

5733-589: The Nagoya Protocol to the Convention on Biological Diversity and its system of Access and Benefit-Sharing . Representatives of Indigenous peoples view the GRATK Treaty as a "first step towards guaranteeing just and transparent access to these resources." Before filing for an application, which must be paid for whether a patent is granted or not, a person will want to ensure that their material

5850-458: The Ogg format can act as a container for different types of multimedia including any combination of audio and video , with or without text (such as subtitles ), and metadata . A text file can contain any stream of characters, including possible control characters , and is encoded in one of various character encoding schemes . Some file formats, such as HTML , scalable vector graphics , and

5967-475: The U.S. Congress was passed on April 10, 1790, titled "An Act to promote the progress of useful Arts". The first patent under the Act was granted on July 31, 1790, to Samuel Hopkins of Vermont for a method of producing potash (potassium carbonate). A revised patent law was passed in 1793, and in 1836 a major revision was passed. The 1836 law instituted a significantly more rigorous application process, including

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6084-465: The WIPO Treaty on Intellectual Property, Genetic Resources and Associated Traditional Knowledge (GRATK Treaty) mandating patent disclosure requirements for patents based on genetic resources and associated traditional knowledge from being granted. The Treaty contemplates revocation for patents incorrectly filed. The treaty, and in particular its planned extension, is seen as complementing

6201-762: The World Trade Organization (WTO) being particularly active in this area. The TRIPS Agreement has been largely successful in providing a forum for nations to agree on an aligned set of patent laws. Conformity with the TRIPS agreement is a requirement of admission to the WTO and so compliance is seen by many nations as important. This has also led to many developing nations, which may historically have developed different laws to aid their development, enforcing patents laws in line with global practice. Internationally, there are international treaty procedures, such as

6318-468: The source code of computer software are text files with defined syntaxes that allow them to be used for specific purposes. File formats often have a published specification describing the encoding method and enabling testing of program intended functionality. Not all formats have freely available specification documents, partly because some developers view their specification documents as trade secrets , and partly because other developers never author

6435-575: The 18th century through a slow process of judicial interpretation of the law. During the reign of Queen Anne , patent applications were required to supply a complete specification of the principles of operation of the invention for public access. Legal battles around the 1796 patent taken out by James Watt for his steam engine , established the principles that patents could be issued for improvements of an already existing machine and that ideas or principles without specific practical application could also legally be patented. The English legal system became

6552-471: The ASCII representation formed a sequence of meaningful characters, such as an abbreviation of the application's name or the developer's initials. For instance a HyperCard "stack" file has a creator of WILD (from Hypercard's previous name, "WildCard") and a type of STAK . The BBEdit text editor has a creator code of R*ch referring to its original programmer, Rich Siegel . The type code specifies

6669-513: The PUID scheme does provide greater granularity than most alternative schemes. MIME types are widely used in many Internet -related applications, and increasingly elsewhere, although their usage for on-disc type information is rare. These consist of a standardised system of identifiers (managed by IANA ) consisting of a type and a sub-type , separated by a slash —for instance, text/html or image/gif . These were originally intended as

6786-787: The UK, substantive patent law is contained in the Patents Act 1977 as amended. In the United States, the Constitution empowers Congress to make laws to "promote the Progress of Science and useful Arts ...". The laws Congress passed are codified in Title 35 of the United States Code and created the United States Patent and Trademark Office . There is a trend towards global harmonization of patent laws, with

6903-545: The US, plant breeders' rights are sometimes called plant patents , and utility models and Gebrauchsmuster are sometimes called petty patents or innovation patents . The additional qualification utility patent is sometimes used (primarily in the US) to distinguish the primary meaning from these other types of patents. Particular types of patents for inventions include biological patents , business method patents , chemical patents and software patents . Although there

7020-751: The VSAM catalog (prior to ICF catalogs ) and the VSAM Volume Record in the VSAM Volume Data Set (VVDS) (with ICF catalogs) identifies the type of VSAM dataset. In IBM OS/360 through z/OS , a format 1 or 7 Data Set Control Block (DSCB) in the Volume Table of Contents (VTOC) identifies the Dataset Organization ( DSORG ) of the dataset described by it. The HPFS , FAT12, and FAT16 (but not FAT32) filesystems allow

7137-445: The applicant) who might seek patent protection for the invention in those countries. Commonly, a nation or a group of nations forms a patent office with responsibility for operating that nation's patent system, within the relevant patent laws. The patent office generally has responsibility for the grant of patents, with infringement being the remit of national courts. The authority for patent statutes in different countries varies. In

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7254-442: The appropriate icons, but these will be located in different places on the storage medium thus taking longer to access. A folder containing many files with complex metadata such as thumbnail information may require considerable time before it can be displayed. If a header is binary hard-coded such that the header itself needs complex interpretation in order to be recognized, especially for metadata content protection's sake, there

7371-530: The benefits of using each other's patented inventions. Freedom Licenses like the Apache 2.0 License are a hybrid of copyright/trademark/patent license/contract due to the bundling nature of the three intellectual properties in one central license. This can make it difficult to enforce because patent licenses cannot be granted this way under copyright and would have to be considered a contract. In most countries, both natural persons and corporate entities may apply for

7488-454: The command interpreter. Another operating system using magic numbers is AmigaOS , where magic numbers were called "Magic Cookies" and were adopted as a standard system to recognize executables in Hunk executable file format and also to let single programs, tools and utilities deal automatically with their saved data files, or any other kind of file types when saving and loading data. This system

7605-431: The computer. The same is true with files with only one extension: as it is not shown to the user, no information about the file can be deduced without explicitly investigating the file. To further trick users, it is possible to store an icon inside the program, in which case some operating systems' icon assignment for the executable file ( .exe ) would be overridden with an icon commonly used to represent JPEG images, making

7722-400: The course of the 20th and 21st centuries, however, disparity is still prevalent. In the UK, for example, only 8% of inventors were female as of 2015. This can partly be attributed to historical barriers for women to obtain patents, as well as to the fact that women are underrepresented in traditionally "patent-intensive" sectors, particularly STEM sectors. Marcowitz-Bitton et al. argue that

7839-419: The data must be entirely parsed by applications. On Unix and Unix-like systems, the ext2 , ext3 , ext4 , ReiserFS version 3, XFS , JFS , FFS , and HFS+ filesystems allow the storage of extended attributes with files. These include an arbitrary list of "name=value" strings, where the names are unique and a value can be accessed through its related name. The PRONOM Persistent Unique Identifier (PUID)

7956-430: The destination, the single file received has to be unzipped by a compatible utility to be useful. The problems of handling metadata are solved this way using zip files or archive files. The Mac OS ' Hierarchical File System stores codes for creator and type as part of the directory entry for each file. These codes are referred to as OSTypes. These codes could be any 4-byte sequence but were often selected so that

8073-654: The establishment of an examination system. Between 1790 and 1836 about ten thousand patents were granted. By the American Civil War about 80,000 patents had been granted. In the US, married women were historically precluded from obtaining patents. While section 1 of the Patent Act of 1790 did refer to "she", married women were unable to own property in their own name and were also prohibited from rights to their own income, including income from anything they invented. This historical gender gap has lessened over

8190-435: The file during the loading process and afterwards. File headers may be used by an operating system to quickly gather information about a file without loading it all into memory, but doing so uses more of a computer's resources than reading directly from the directory information. For instance, when a graphic file manager has to display the contents of a folder, it must read the headers of many files before it can display

8307-448: The file format's definition. Throughout the 1970s, many programs used formats of this general kind. For example, word-processors such as troff , Script , and Scribe , and database export files such as CSV . Electronic Arts and Commodore - Amiga also used this type of file format in 1985, with their IFF (Interchange File Format) file format. A container is sometimes called a "chunk" , although "chunk" may also imply that each piece

8424-831: The file, each of which is a string, such as "Plain Text" or "HTML document". Thus a file may have several types. The NTFS filesystem also allows storage of OS/2 extended attributes, as one of the file forks , but this feature is merely present to support the OS/2 subsystem (not present in XP), so the Win32 subsystem treats this information as an opaque block of data and does not use it. Instead, it relies on other file forks to store meta-information in Win32-specific formats. OS/2 extended attributes can still be read and written by Win32 programs, but

8541-647: The first modern patent system that recognised intellectual property in order to stimulate invention; this was the crucial legal foundation upon which the Industrial Revolution could emerge and flourish. By the 16th century, the English Crown would habitually abuse the granting of letters patent for monopolies . After public outcry, King James I of England (VI of Scotland ) was forced to revoke all existing monopolies and declare that they were only to be used for "projects of new invention". This

8658-443: The format exist: qcow, qcow2 and qcow3 which use the .qcow , .qcow2 and .qcow3 file extensions, respectively. qemu-img command allows to inspect, check, create, convert, resize and take snapshot of qcow images. The e2fsprogs command e2image also has support for generating qcow2 files to avoid the use of sparse file support. One of the main characteristics of qcow disk images is that files with this format can grow as data

8775-471: The format of the file, while the creator code specifies the default program to open it with when double-clicked by the user. For example, the user could have several text files all with the type code of TEXT , but each open in a different program, due to having differing creator codes. This feature was intended so that, for example, human-readable plain-text files could be opened in a general-purpose text editor, while programming or HTML code files would open in

8892-463: The format will be identified correctly, and can often determine more precise information about the file. Since reasonably reliable "magic number" tests can be fairly complex, and each file must effectively be tested against every possibility in the magic database, this approach is relatively inefficient, especially for displaying large lists of files (in contrast, file name and metadata-based methods need to check only one piece of data, and match it against

9009-586: The format's developers for a fee and by signing a non-disclosure agreement . The latter approach is possible only when a formal specification document exists. Both strategies require significant time, money, or both; therefore, file formats with publicly available specifications tend to be supported by more programs. Patent law, rather than copyright , is more often used to protect a file format. Although patents for file formats are not directly permitted under US law, some formats encode data using patented algorithms . For example, prior to 2004, using compression with

9126-630: The foundation for patent law in countries with a common law heritage, including the United States, New Zealand and Australia . In the Thirteen Colonies , inventors could obtain patents through petition to a given colony's legislature. In 1641, Samuel Winslow was granted the first patent in North America by the Massachusetts General Court for a new process for making salt. The modern French patent system

9243-404: The full term, while small companies are more likely to abandon their patents earlier, even though the due fees are ca. 5 times lower for small businesses (microentities). The costs of preparing and filing a patent application, prosecuting it until grant and maintaining the patent vary from one jurisdiction to another, and may also be dependent upon the type and complexity of the invention, and on

9360-510: The gender gap in patents is also a result of internal bias within the patent system. The number of patent applications filed each year has been growing for most countries although not smoothly, and jumps in activity are often observed due to changes in local laws. The high number of patent families for Spain in the 1800s is related to the superior preservation and cataloguing of the data by Spanish Patent and Trademark Office compared to other countries (see 1836 U.S. Patent Office fire ). The US

9477-502: The international phase 3. Examination during the national phase. Alongside these international agreements for patents there was the Patent Law Treaty (PLT). This treaty standardized the filing date requirements, standardized the application and forms, allows for electronic communication and filing, and avoids unintentional loss of rights, and simplifies patent office procedures. Sometimes, nations grant others, other than

9594-415: The invention be exploited in the jurisdiction it covers. Consequences of not working an invention vary from one country to another, ranging from revocation of the patent rights to the awarding of a compulsory license awarded by the courts to a party wishing to exploit a patented invention. The patentee has the opportunity to challenge the revocation or license, but is usually required to provide evidence that

9711-571: The inventor's normal or specifically assigned employment duties, where an invention might reasonably be expected to result from carrying out those duties, or if the inventor had a special obligation to further the interests of the employer's company. Applications by artificial intelligence systems, such as DABUS , have been rejected in the US, the UK, and at the European Patent Office on the grounds they are not natural persons. The inventors, their successors or their assignees become

9828-437: The licensee the right to make, use, sell, or import the claimed invention, usually in return for a royalty or other compensation. It is common for companies engaged in complex technical fields to enter into multiple license agreements associated with the production of a single product. Moreover, it is equally common for competitors in such fields to license patents to each other under cross-licensing agreements in order to share

9945-515: The main data and the name, but is also less portable than either filename extensions or "magic numbers", since the format has to be converted from filesystem to filesystem. While this is also true to an extent with filename extensions— for instance, for compatibility with MS-DOS 's three character limit— most forms of storage have a roughly equivalent definition of a file's data and name, but may have varying or no representation of further metadata. Note that zip files or archive files solve

10062-430: The memory images also have reserved spaces for future extensions, extending and improving this type of structured file is very difficult. It also creates files that might be specific to one platform or programming language (for example a structure containing a Pascal string is not recognized as such in C ). On the other hand, developing tools for reading and writing these types of files is very simple. The limitations of

10179-671: The most significant aspect of the convention is the provision of the right to claim priority : filing an application in any one member state of the Paris Convention preserves the right for one year to file in any other member state, and receive the benefit of the original filing date. Another key treaty is the Patent Cooperation Treaty (PCT), administered by the World Intellectual Property Organization (WIPO) and covering more than 150 countries. The Patent Cooperation Treaty provides

10296-511: The original version is that qcow2 supports multiple snapshots using a newer, more flexible model for storing them. The official documentation for the format is part of the QEMU Git tree. File format Some file formats are designed for very particular types of data: PNG files, for example, store bitmapped images using lossless data compression . Other file formats, however, are designed for storage of several different types of data:

10413-399: The patent application to determine if it meets the patentability requirements of that country. If the application does not comply, objections are communicated to the applicant or their patent agent or attorney through an Office action , to which the applicant may respond. The number of Office actions and responses that may occur vary from country to country, but eventually a final rejection

10530-400: The patent owner seeks monetary compensation ( damages ) for past infringement, and seeks an injunction that prohibits the defendant from engaging in future acts of infringement, or seeks either damages or injunction. To prove infringement, the patent owner must establish that the accused infringer practises all the requirements of at least one of the claims of the patent. (In many jurisdictions

10647-488: The patent owner the right to exploit the invention subject to the patent. For example, many inventions are improvements of prior inventions that may still be covered by someone else's patent. If an inventor obtains a patent on improvements to an existing invention which is still under patent, they can only legally use the improved invention if the patent holder of the original invention gives permission, which they may refuse. Some countries have "working provisions" that require

10764-427: The patent owner will have no legal grounds for enforcing the patent in country B as it was already sold in a different country. Patents can generally only be enforced through civil lawsuits (for example, for a US patent, by an action for patent infringement in a United States federal district court), although some countries (such as France and Austria ) have criminal penalties for wanton infringement. Typically,

10881-544: The patent owner, permissions to create a patented product based on different situations that align with public policy or public interest. These may include compulsory licenses, scientific research, and in transit in country. After two decades of drafting, the WIPO 's Intergovernmental Committee on Intellectual Property and Genetic Resources, Traditional Knowledge and Folklore moved to a Diplomatic Conference in May 2024 and adopted

10998-562: The patent should never have been granted. There are several grounds for challenges: the claimed subject matter is not patentable subject matter at all; the claimed subject matter was actually not new, or was obvious to the person skilled in the art , at the time the application was filed; or that some kind of fraud was committed during prosecution with regard to listing of inventors, representations about when discoveries were made, etc. Patents can be found to be invalid in whole or in part for any of these reasons. Patent infringement occurs when

11115-665: The patentee, and the extent of the exclusive rights vary widely between countries according to national laws and international agreements. Typically, however, a patent application must include one or more claims that define the scope of protection that is being sought. A patent may include many claims, each of which defines a specific property right. Under the World Trade Organization 's (WTO) TRIPS Agreement , patents should be available in WTO member states for any invention, in all fields of technology , provided they are new , involve an inventive step , and are capable of industrial application . Nevertheless, there are variations on what

11232-436: The path to the base image to be able to refer back to it when required. When a particular piece of data has to be read from this new image, the content is retrieved from it if it is new and was stored there; if it is not, the data is fetched from the base image. Optional features include zlib -based transparent decompression . qcow2 is an updated version of the qcow format. qcow2 supports AES encryption. The difference from

11349-679: The permission of the other proprietor(s). The ability to assign ownership rights increases the liquidity of a patent as property. Inventors can obtain patents and then sell them to third parties. The third parties then own the patents and have the same rights to prevent others from exploiting the claimed inventions, as if they had originally made the inventions themselves. The grant and enforcement of patents are governed by national laws, and also by international treaties, where those treaties have been given effect in national laws. Patents are granted by national or regional patent offices, i.e. national or regional administrative authorities. A given patent

11466-416: The problem of handling metadata. A utility program collects multiple files together along with metadata about each file and the folders/directories they came from all within one new file (e.g. a zip file with extension .zip ). The new file is also compressed and possibly encrypted, but now is transmissible as a single file across operating systems by FTP transmissions or sent by email as an attachment. At

11583-690: The procedures under the European Patent Convention (EPC) [constituting the European Patent Organisation (EPOrg)], that centralize some portion of the filing and examination procedure. Similar arrangements exist among the member states of ARIPO and OAPI , the analogous treaties among African countries, and the nine CIS member states that have formed the Eurasian Patent Organization . A key international convention relating to patents

11700-447: The program look like an image. Extensions can also be spoofed: some Microsoft Word macro viruses create a Word file in template format and save it with a .doc extension. Since Word generally ignores extensions and looks at the format of the file, these would open as templates, execute, and spread the virus. This represents a practical problem for Windows systems where extension-hiding is turned on by default. A second way to identify

11817-443: The proprietors of the patent when and if it is granted. If a patent is granted to more than one proprietor, the laws of the country in question and any agreement between the proprietors may affect the extent to which each proprietor can exploit the patent. For example, in some countries, each proprietor may freely license or assign their rights in the patent to another person while the law in other countries prohibits such actions without

11934-400: The reasonable requirements of the public have been met by the working of invention. In most jurisdictions, there are ways for third parties to challenge the validity of an allowed or issued patent at the national patent office; these are called opposition proceedings . It is also possible to challenge the validity of a patent in court. In either case, the challenging party tries to prove that

12051-437: The relevant area of technology) to make and use the invention. In some countries there are requirements for providing specific information such as the usefulness of the invention, the best mode of performing the invention known to the inventor, or the technical problem or problems solved by the invention. Drawings illustrating the invention may also be provided. The application also includes one or more claims that define what

12168-468: The relevant country. Although an infringer is generally free to rely on any available ground of invalidity (such as a prior publication , for example), some countries have sanctions to prevent the same validity questions being relitigated. An example is the UK Certificate of contested validity . Patent licensing agreements are contracts in which the patent owner (the licensor) agrees to grant

12285-502: The right granted to anyone who invents something new, useful and non-obvious. A patent is often referred to as a form of intellectual property right, an expression which is also used to refer to trademarks and copyrights , and which has proponents and detractors (see also Intellectual property § The term "intellectual property" ). Some other types of intellectual property rights are also called patents in some jurisdictions: industrial design rights are called design patents in

12402-819: The same thing as identifiers in the sense of a database key or serial number (although an identifier may well identify its associated data as such a key). With this type of file structure, tools that do not know certain chunk identifiers simply skip those that they do not understand. Depending on the actual meaning of the skipped data, this may or may not be useful ( CSS explicitly defines such behavior). This concept has been used again and again by RIFF (Microsoft-IBM equivalent of IFF), PNG, JPEG storage, DER ( Distinguished Encoding Rules ) encoded streams and files (which were originally described in CCITT X.409:1984 and therefore predate IFF), and Structured Data Exchange Format (SDXF) . Indeed, any data format must somehow identify

12519-443: The scope of the patent may not be limited to what is literally stated in the claims, for example due to the doctrine of equivalents .) An accused infringer has the right to challenge the validity of the patent allegedly being infringed in a counterclaim . A patent can be found invalid on grounds described in the relevant patent laws, which vary between countries. Often, the grounds are a subset of requirements for patentability in

12636-530: The significance of its component parts, and embedded boundary-markers are an obvious way to do so: This is another extensible format, that closely resembles a file system ( OLE Documents are actual filesystems), where the file is composed of 'directory entries' that contain the location of the data within the file itself as well as its signatures (and in certain cases its type). Good examples of these types of file structures are disk images , executables , OLE documents TIFF , libraries . Patent A patent

12753-586: The standard to which they adhere. Many file types, especially plain-text files, are harder to spot by this method. HTML files, for example, might begin with the string <html> (which is not case sensitive), or an appropriate document type definition that starts with <!DOCTYPE html , or, for XHTML , the XML identifier, which begins with <?xml . The files can also begin with HTML comments, random text, or several empty lines, but still be usable HTML. The magic number approach offers better guarantees that

12870-438: The storage of "extended attributes" with files. These comprise an arbitrary set of triplets with a name, a coded type for the value, and a value, where the names are unique and values can be up to 64 KB long. There are standardized meanings for certain types and names (under OS/2 ). One such is that the ".TYPE" extended attribute is used to determine the file type. Its value comprises a list of one or more file types associated with

12987-431: The university's patenting activity plateaued in the 2010s. Incidentally, only 20% of Stanford patents in that dataset produced a positive net income for the university, while the rest was a net loss. Similar declines have been noted not only for the number of patents, but also for other measures of innovation output. Several hypotheses have been proposed as explanations for the observed decline: A patent does not give

13104-414: The unstructured formats led to the development of other types of file formats that could be easily extended and be backward compatible at the same time. In this kind of file structure, each piece of data is embedded in a container that somehow identifies the data. The container's scope can be identified by start- and end-markers of some kind, by an explicit length field somewhere, or by fixed requirements of

13221-472: The use of this standard awkward in some cases. File format identifiers are another, not widely used way to identify file formats according to their origin and their file category. It was created for the Description Explorer suite of software. It is composed of several digits of the form NNNNNNNNN-XX-YYYYYYY . The first part indicates the organization origin/maintainer (this number represents

13338-472: Was created during the Revolution in 1791. Patents were granted without examination since inventor's right was considered as a natural one. Patent costs were very high (from 500 to 1,500 francs). Importation patents protected new devices coming from foreign countries. The patent law was revised in 1844 – patent cost was lowered and importation patents were abolished. The first Patent Act of

13455-612: Was incorporated into the Statute of Monopolies (1624) in which Parliament restricted the Crown's power explicitly so that the King could only issue letters patent to the inventors or introducers of original inventions for a fixed number of years. The Statute became the foundation for later developments in patent law in England and elsewhere. Important developments in patent law emerged during

13572-596: Was the World's leader in terms of patent families filed between 1900 and 1966, when Japan took over. Since 2007 PR China leads. However, in most technologically advanced countries (see, for example, France, Italy, Japan, Spain, Sweden, the UK in the figure on the right, as well as in Poland ), the total (i.e. regardless of the priority/inventors' country) number of patent families filed there have been declining in absolute numbers since c.  1970s –1980s. The decline

13689-579: Was then enhanced with the Amiga standard Datatype recognition system. Another method was the FourCC method, originating in OSType on Macintosh, later adapted by Interchange File Format (IFF) and derivatives. A final way of storing the format of a file is to explicitly store information about the format in the file system, rather than within the file itself. This approach keeps the metadata separate from both

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