To complete your initial logon process, you will need to know your Personnel Office Identifier (POID) and your 18 digit Organization Code. Please reach out to your HR Servicing Office with assistance in obtaining this information. How to Register to Access Your Electronic Official Personnel Folder (eOPF). Opf Reader free download - ZIP Reader, Adobe Acrobat Reader DC, PDF Reader for Windows 7, and many more programs.
- The OPF files store information for an associated eBook including the title of the eBook, the eBook language, creator, reading order and book ID. The OPF file is included in the EPUB archive to specify the metadata of the associated eBook. The OPF files are saved in.
- Feb 07, 2019 OPF files are saved in E-Book Systems' proprietary FlipAlbum XML format, and should not be confused with the Open Packaging Format (OPF) standard. NOTE: FlipAlbum has been discontinued and is no longer available for download.
Many people share .opf files without attaching instructions on how to use it. Yet it isn’t evident for everyone which program a .opf file can be edited, converted or printed with. On this page, we try to provide assistance for handling .opf files.
3 filename extension(s) found in our database.
.opf - Obsidium Project File
Opf Files Opening
The OPF development files are related to Obsidium. OPF is an Obsidium Project File. Obsidium is a software protection system.
- Application:
- Obsidium
- Category:
- Development files
- Mime-type:
- application/octet-stream
- Magic:
- - / -
- Aliases:
- -
- Obsidium Project File related extensions:
- .xsym
- CodeWarrior xSYM File
- .nvv
- Nvidia Vertex Shader Profile
- .nuspec
- NuGet Specification Data
- .nupkg
- NuGet Package
- .ptm
- Portable Translation Memories
- .wln
- Novell Localisation Workbench Workspace
![How to read of files How to read of files](/uploads/1/3/4/7/134777103/349079134.png)
.opf - Open Electronic Package Ebook
The OPF ebook files are related to Calibre. OPF file is an Open Electronic Package Ebook. OPF is an XML-based e-book format created by E-Book Systems; it has been superseded by the EPUB electronic publication standard.
- Application:
- Calibre
- Category:
- Ebook files
- Mime-type:
- application/octet-stream
- Magic:
- - / -
- Aliases:
- oeb
- Open Electronic Package Ebook related extensions:
- .calibre
- Calibre Device Information Data
- .cbc
- Comic Book Collection
- .htmlz
- Zipped HTML eBook
- .lrf
- Sony BBeB E-Book
- .lrs
- Sony BBeB E-Book Source
- .ncx
- EPUB Navigation Control XML
.opf - Concordance Print Settings Data
The OPF data files are related to Concordance. OPF file is a Concordance Print Settings Data. Concordance is an electronic discovery, litigation document management, and litigation support tool.
- Application:
- Concordance
- Category:
- Data files
- Mime-type:
- application/octet-stream
- Magic:
- - / -
- Aliases:
- -
- Concordance Print Settings Data related extensions:
- .cat
- Concordance Database Concatenation Data
- .cib
- Concordance Imagebase File
- .cpl
- Concordance Desktop Programming Language Script
- .cpt
- Concordance Compiled CPT Script
- .dcb
- Concordance Database
- .dct
- Concordance Dictionary Database
Naturally, other applications may also use the .opf file extension. Even harmful programs can create .opf files. Be especially cautious with .opf files coming from an unknown source!
Can't open a .opf file?
When you double-click a file to open it, Windows examines the filename extension. If Windows recognizes the filename extension, it opens the file in the program that is associated with that filename extension. When Windows does not recognize a filename extension, you receive the following message:
Windows can't open this file:
example.opf
To open this file, Windows needs to know what program you want to use to open it. Windows can go online to look it up automatically, or you can manually select one from a list of programs that are installed on your computer.
example.opf
To open this file, Windows needs to know what program you want to use to open it. Windows can go online to look it up automatically, or you can manually select one from a list of programs that are installed on your computer.
To avoid this error, you need to set the file association correctly.
- Open Control Panel > Control Panel Home > Default Programs > Set Associations.
- Select a file type in the list and click Change Program.
The .opf file extension is often given incorrectly!
According to the searches on our site, these misspellings were the most common in the past year:
ipf, kpf, lpf, ofp, olf, oof, op, opb, opc, opd, ope, opg, opr, opt, opv
Is it possible that the filename extension is misspelled?
Similar file extensions in our database:
- .opt
- Altair FEKO CADFEKO Optimisation Data
- .opt
- Microsoft Visual Studio Workspace Options
- .opt
- ProWorx NXT List Module Option File
- .opt
- Concordance Native Viewer Database
- .opt
- µVision Project Options Data
- .ipf
- Intercept Part File
Operating systems
DataTypes.net currently supports the following operating systems:
Windows XP/Vista, Windows 7/8, Windows 10, CentOS, Debian GNU/Linux, Ubuntu Linux, FreeBSD, Mac OS X, iOS, Android
If you find the information on this page useful, please feel free to link to this page.
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An EPUB 3 archive has a skeleton – the files which are mandatory to structure the content – and some flesh – the ebook content.
As explained in the introduction, the flesh is a set of (X)HTML 5 and CSS resources, javascript code, images, audio and video assets. Let’s focus on the skeleton then, which is specified as the EPUB Open Container Format (OCF).
Mime type
The first file you may spot in the zip archive is the mimetype file, which states that this archive is *really* an EPUB publication.
The content of this text file must be “application/epub+zip” and nothing else. This is how an EPUB reading system will assured he can process the ebook.
Opf File Va
It is required that the mimetype file is the first file found in the zip archive. This may appear a weird constraint, but as a matter of fact this constraint originates in the Open Document file format which was the source of the EPUB file format. The rationale behind it is that if an application reads the first bytes of the archive, it will always find the same “magic numbers” (see here for OCF magic numbers). This can replace the detection of the format in case the file extension .epub is not reliable.
A practical issue with this requirement is that one cannot create a proper EPUB file with a simple zip tool: generic tools cannot guarantee that the mimetype file will be first in the archive.
container.xml
This small XML file, found in the mandatory META-INF directory, is a bootstrapping item. It simply contains the relative location of the .opf file (a.k.a. package document), which is the brain of the publication and will be described shortly.
If the content.opf file is for instance in the folder content in the archive, then the location will be content/content.opf.
Using this information, the reading system will be able to open the .opf file and know more about structure of the publication.
EPUB 3 supports multiple renditions of an EPUB publication. You may find for instance a fixed-layout rendition and a reflowable rendition packaged in the same EPUB file. In such a case, container.xml will reference several package documents usually placed in several directories.
Apart from container.xml, you may find other files in the META-INF directory, like signatures.xmlwhich holds digital signatures of the container and its contents, metadata.xml and manifest.xml which may contain information about the publication itself (i.e. the container; this is useful in the multiple renditions use case), or proprietary files like com.apple.ibooks.display-options.xml. Their presence is rather exceptional, therefore we won’t describe them in details here.
The .opf file, a.k.a package document
This XML file carries bibliographic and structural metadata about an EPUB publication (or an EPUB rendition), and is thus the primary source of information about how to process and display that publication.
In this file, the reading system will find:
Some metadata
i.e. information about the publication (or rendition) content. Diverse sets of metadata (e.g. Onyx) can be expressed as XML elements, from different schemes. The only required elements in EPUB 3.01 are title, identifier, language and modified, from the Dublin Core set. A fixed-layout publication must be tagged by a specific metadata item in this set. Other metadata can be expressed inline, using a generic meta element, or as an external resource via a link element.
A manifest
i.e. the exhaustive list of all publication (or rendition) resources, including (x)html text chapters, images and videos or audio files, fonts, scripts, css files. The reading system will only process the files it finds in the list, and knows from their media type (a.k.a. mime type) that it can process them. From the properties declared on each item, the reading system will also know its type, e.g. if the file corresponds to a navigation document, cover image, vector graphic or a script. If the reading system cannot process the resource because its format is a bit exotic, it will find here the fallback resource he can process instead.
A spine
As its name indicates, this is a “backbone” where the reading system finds the default reading order of all publication “chapters”. As these sections of a publication may not really represent book chapters, each item of the sequence is called … a spine item. Each spine item contains a reference to a manifest item. Spine items can be declared as “non linear”, meaning they are not displayed in the normal flow, but can be reached from another spine item as supplementary content (e.g. popup content).
Below is a simple package document with metadata, a manifest and a spine.
The legacy .ncx file
A quick word about this file, sometime found in EPUB 3 containers: this is the deprecated EPUB 2 way of declaring a navigation document. Some EPUB 3 authors still prefer to include it so that EPUB 2 reading systems can process the publication. An EPUB 3 reading system will not access it, so we won’t bother describing its content.
A simple diagram to summarize this
Here is a diagram illustrating the complete structure of an EPUB file.
In this example, we find the .opf file and all content files in a directory named “OEBPS”. Why such a strange name? This is simply historical: Open eBook Publication Structure was the name of a legacy ebook format which has been superseded by the EPUB format. The acronym found its way in the publishing vocabulary and is still used by some EPUB authoring tools when they structure an EPUB publication, so that the .opf file and content files are not stored in the root of the EPUB archive (something which would still be harmless by the way).
Readium
The Readium projects provide rock-solid, performant building blocks and applications for processing EPUB3 publications. EDRLab is participating to the Readium codebase maintenance and evolution.
Accessibility
Support for people wih print disabilities is a key part of our mission. We collaborate with European publishers and major inclusing organizations on the creation of a born-accessible ebook market. We also make sure that Readium projects take into account the assistive technologies used by visually-impaired users.