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80-598: PRONOM ( Public Record Office and Nôm 喃 ) is a web -based technical registry to support digital preservation services, developed by The National Archives of the United Kingdom . PRONOM was the first and remains, to date, the only operational public file format registry in the world, although the "Magic File" repository of the File Command has served this role in a less formal capacity for two decades. Other projects to develop technical registries, including

160-434: 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

240-408: 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,

320-520: 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

400-448: 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

480-401: 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

560-416: 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,

640-419: A form which can only be processed and rendered comprehensible by very specific technological environments. The accessibility of that information is therefore highly vulnerable to technological obsolescence . Technical information about the structure of those file formats, and the software and hardware environments required to support them, is therefore a prerequisite for any digital preservation regime. PRONOM

720-401: 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

800-399: 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 ,

880-470: A limited number of documents. These charges were abolished for serious historical and literary researchers after a petition was signed in 1851 by 83 people including Charles Dickens and the historians Lord Macaulay and Thomas Carlyle . Between 1851 and 1858 a purpose-built archive repository was built next to the Rolls Chapel, to the design of the architect Sir James Pennethorne , and following

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960-442: 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

1040-414: 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

1120-408: 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

1200-541: A series of six Royal Commissions of Great Britain and (from 1801) the United Kingdom which sat between 1800 and 1837 to inquire into the custody and public accessibility of the state archives . The Commissions emphasised the poor conditions and variety of places in which records were held. As a result, the Public Record Office Act 1838 ( 1 & 2 Vict. c. 94) was passed to "keep safely

1280-441: 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

1360-431: 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)

1440-485: 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

1520-502: 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

1600-638: 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

1680-428: 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

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1760-528: 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

1840-444: Is a platform-independent Java tool. It includes a documented, public API , and can be invoked from both GUI and command line interfaces. Proposed future services include format risk assessments and preservation planning, and the automated generation of migration pathways for converting between formats. Public Record Office The Public Record Office (abbreviated as PRO , pronounced as three letters and referred to as

1920-407: 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,

2000-464: Is a software tool developed by The National Archives to perform automated batch identification of file formats. It is one of a planned series of tools utilising PRONOM to provide specific digital preservation services. DROID uses internal (byte sequence) and external (file extension) signatures to identify and report the specific file format versions of digital files. These signatures are stored in an XML signature file, generated from information recorded in

2080-476: Is an extensible scheme of persistent, unique and unambiguous identifiers for records in the PRONOM registry. Such identifiers are fundamental to the exchange and management of digital objects, by allowing human or automated user agents to unambiguously identify, and share that identification of, the representation information required to support access to an object. This is a virtue both of the inherent uniqueness of

2160-449: 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,

2240-685: Is now the Maughan Library , the university's largest library. In April 2003 the PRO merged with the Historical Manuscripts Commission (HMC) to form The National Archives . The HMC moved from its previous office, also located off Chancery Lane, to Kew in 2004. The National Archives of Scotland and the Public Record Office of Northern Ireland were and remain separate institutions. The archive held

2320-424: 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

2400-427: 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

2480-648: 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

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2560-479: 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

2640-510: The info:pronom/ namespace, details of which are available from the info URI registry. Neither the PUID scheme, nor its expression as an info URI, supports any inherent dereferencing mechanism, i.e. a PUID does not resolve to a Uniform Resource Locator . However, The National Archives is planning to develop a range of services to expose PRONOM registry content, including a resolution service for PUIDs. DROID (Digital Record Object Identification)

2720-485: The Chapter House of Westminster Abbey , though Domesday Book was not moved from Westminster Abbey until 1859, when proper storage had been prepared. Until 1852 no right existed for the general public to consult the records freely, even for scholarly purposes, despite the intention of the Public Record Office Act 1838 to enable public access. Fees were payable by lawyers who in return were permitted to consult

2800-638: 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

2880-458: 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

2960-717: The PRO), Chancery Lane in the City of London , was the guardian of the national archives of the United Kingdom from 1838 until 2003, when it was merged with the Historical Manuscripts Commission to form The National Archives , based in Kew . It was under the control of the Master of the Rolls , a senior judge. The Public Record Office still exists as a legal entity, as the enabling legislation has not been modified. The Record Commissions were

3040-468: 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

3120-664: The 2007 Digital Preservation Award sponsored by the Digital Preservation Coalition , for its work on PRONOM and DROID. The Global Digital Format Registry project which began at Harvard in 2005 was eventually rolled along with PRONOM into the joint Unified Digital Format Registry effort. In 2012, however, the UDFR was mothballed leading to the California Digital Library eventually removing access to their node in 2016 and recommending

3200-471: 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

3280-609: The PRO. Even so, growing interest in the records produced a need for the Office to expand, and in 1977 a second building was opened at Kew in south-west London. The Kew building was expanded in the 1990s and by 1997 all records had been transferred from Chancery Lane either to Kew or to the Family Records Centre in Islington , North London. The Chancery Lane building was acquired by King's College London in 2001, and

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3360-471: The PRONOM technical registry. New and updated signatures are regularly added to PRONOM, and DROID can be configured to automatically download updated signature files from the PRONOM website via web services . DROID allows files and folders to be selected from a file system for identification. After the identification process had been run, the results can be output in XML , CSV or printer-friendly formats. DROID

3440-462: 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

3520-586: The UK Digital Curation Centre 's Representation Information Registry, and the Global Digital Format Registry project at Harvard University , are now in progress. PRONOM's origins lie in a requirement to have access to reliable technical information about the electronic records held by The National Archives. By definition, electronic records are not inherently human-readable - file formats encode information into

3600-477: The UK's Freedom of Information Act 2000 came into full effect in 2005: the 30 year rule was abolished and closed records in The National Archives became subject to the same access controls as other records of public authorities. Some records do remain closed for longer periods, however: individual census returns, for example, are kept closed for 100 years. From 1838 to 1958 the nominal head of

3680-751: 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

3760-442: 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

3840-471: The border with the City of Westminster . Some of the records were court or departmental archives (established for several centuries) which were well-run and had good or adequate catalogues; others were little more than store-rooms. Many of the professional staff of these individual archives simply continued their existing work in the new institution. Many documents were transferred from the Tower of London and

3920-520: The chapel's demolition due to structural unsoundness, was extended onto that original site between 1895 and 1900. The growing size of the archives held by the PRO and by government departments led to the Public Records Act 1958 , which sought to avoid the indiscriminate retention of huge numbers of documents by establishing standard selection procedures for the identification of those documents of sufficient historical importance to be kept by

4000-454: 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

4080-431: 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

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4160-419: 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)

4240-430: 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

4320-435: 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

4400-448: 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

4480-831: 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

4560-471: 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

4640-463: 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

4720-586: 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

4800-455: The historian Sir Francis Palgrave (who wrote a voluminous work on ancient writs , many of which were housed in the PRO), had full-time responsibility for running the Office. The Office's original premises were the mediaeval Rolls Chapel (the former Domus Conversorum , a chapel for Jews who had converted to Christianity), on Chancery Lane at the western extremity of the City of London , near

4880-498: The identifier, and of its binding to a definitive description of the representation information in a registry such as PRONOM. At present, the PUID scheme is limited to one particular class of representation information: the format in which a digital object is encoded. Formats were considered a particular priority for such a scheme, as no existing, universally applicable system provides for this. Unix magic numbers and Macintosh data forks do provide some of this functionality, but

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4960-515: 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

5040-430: 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

5120-1029: The office, known as the Keeper of the Records, was the Master of the Rolls of the day. The chief executive officer who oversaw the office's day-to-day operations was known as the Deputy Keeper of the Records. Deputy Keepers from 1838 to 1958 were: The 1958 act transferred responsibility for the PRO from the Master of the Rolls to the Lord Chancellor ; and the title of the chief executive was changed to Keeper of Public Records. The Keepers from 1958 to 2003 were: 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:

5200-543: The official collection of records of public business for England, Wales and the central UK government , including the records of court proceedings going back to the Middle Ages , and the original manuscript of Domesday Book . Under the 1958 act, most documents held by the PRO were kept "closed" (or secret ) for 50 years: under an amending act of 1967 this period was reduced to 30 years (the so-called " thirty year rule "). These provisions changed significantly when

5280-416: 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

5360-447: 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

5440-563: The public records". The act established the Public Record Office, a non-ministerial department under the keepership of the Master of the Rolls , a senior judge whose job originally had included responsibility for keeping the records of the Court of Chancery , who appointed a Deputy Keeper as Chief Record Keeper . The first Master of the Rolls to take on this responsibility was Lord Langdale (d.1851) although his Deputy Keeper,

5520-460: The recommended encoding scheme for describing file formats in the latest version of the UK e-Government Metadata Standard . The scheme is designed to be extensible, and may be expanded in future to include other classes of representation information in PRONOM, such as compression methods , character encoding schemes , and operating systems . PUIDs can be expressed as Uniform Resource Identifiers using

5600-570: The same is not true within DOS or Microsoft Windows environments. The three-character file extension is neither standardised nor unique, and is interpreted differently by different environments. Equally, the IANA MIME -type scheme does not provide sufficient granularity or coverage to satisfy the requirements for unique identifiers. The PUID scheme has been developed for the single purpose of providing such identifiers. The scheme has been adopted as

5680-819: 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

5760-538: 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

5840-590: The starting point for the development of PRONOM as a major online resource for the international digital preservation community. PRONOM 4, released in October 2005, includes a significant reworking of the underlying data model to allow the capture of detailed technical information on file formats and support future interoperability with other planned registry systems, and the release of the DROID software for automatic file format identification. The latest version PRONOM 5

5920-438: 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

6000-414: 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

6080-778: The use of PRONOM. The core technical registry supports a number of specific services: The PRONOM registry provides a searchable web database of technical information about file formats, the software tools required to access them, and the technical environments required to access them. Users can search for formats and software using a variety of criteria, such as format or software name and file extension . PRONOM also holds information about support periods for software products, and can also be queried on this basis. In addition to on-screen viewing, registry information can be exported in XML , CSV and printer-friendly formats. The PRONOM website allows users to submit new information for inclusion in PRONOM. The PRONOM Persistent Unique Identifier (PUID)

6160-472: 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

6240-483: Was a relatively minor update to support improvements to DROID and was released in 2006. A much more substantial update is planned for 2007, which will include the exposure of core PRONOM functions through web services interfaces . This work forms part of the Seamless Flow programme to position The National Archives to receive and manage future government records in electronic formats. The National Archives won

6320-639: Was developed to provide this function, initially as an internal resource for National Archives staff, and subsequently as public, web-based resource. The first version of PRONOM was developed by The National Archives digital preservation department led by David Ryan in March 2002. PRONOM 2 was released in December 2002, and provided support for the development of multi-lingual versions of the registry. The web-enabling of PRONOM (PRONOM 3) in February 2004 represented

6400-579: 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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