XLIFF is a file format that is used exclusively in the fields of translation and localization and that has become increasingly popular in recent years.
The acronym XLIFF stands for XML Localization Interchange File Format. Thus, XLIFF is an XML-based file format for the exchange of translation and localization data. "XML-based" means that XLIFF is an XML application and is based on the rules of XML.
XLIFF is used for the loss-free, file format-independent, and layout-independent exchange of texts to be translated. As a general rule, the exchange can take place between all tools and systems that support XLIFF. Often, the translation data are exchanged between translation management systems (TMS). However, they can also be exchanged between TMS and other systems in which language resources are entered or managed, e.g. (web) content management systems for creating and maintaining websites or systems from the field of software development. "File format-independent" means that XLIFF serves as a kind of meta file format, i.e. the data are not provided in a specific file format such as Word, PowerPoint, HTML, or InDesign, but merely in a single format: XLIFF.
To generate XLIFF files, the data to be translated are first extracted from the source files. Subsequently, the data to be translated are formatted according to the XLIFF standard and stored in an XLIFF file.
After the translation, the translated XLIFF file is converted back to the original format.
XLIFF is highly versatile in terms of the possible contents of XLIFF files. Of course, XLIFF files contain the source segments to be translated. Additionally, however, XLIFF files can also contain other data, such as context information, matches, and terminology entries. What is more, a single XLIFF file may contain content from multiple source files.
XLIFF files usually have the file extension .xlf or .xliff. As far as the functionality or content is concerned, there is no difference between files with these two extensions.
Being an extensible format, the XLIFF standard enables the creation of user-defined variants or extensions of XLIFF. Apart from the "conventional" XLIFF format, some proprietary XLIFF extensions have been developed (e.g. for a specific tool or system).
Before setting up a project, it must be checked what specific content the XLIFF file has.
Bilingual XLIFF files
XLIFF files can be bilingual, i.e. apart from the source text, they may already contain the translation. The translation does not need to be complete, i.e. only individual segments may be translated. By default, the translations in bilingual XLIFF files are imported during project setup and displayed in the crossDesk translation editor. In certain application scenarios, however, the source text may be inserted instead of the translation (e.g. if the XLIFF file to be translated originates from a content management system). Usually, there is no point in importing such target-language content. Prior to the translation, it should therefore be checked what kind of XLIFF file is on hand. (To do so, open the file (e.g. in a conventional text editor).) If necessary, activate the option "Ignore target content" in the document settings template of XLIFF (under >>Tools >>System Settings... >>Document Settings >>XLIFF).
Translating XLIFF Documents
with the Across Translator Edition
As XLIFF is an XML-based document format, the procedure for the translation of XLIFF files is similar to that for the translation of XML files. Apart from normal text, XLIFF files also contain inline elements and some other features that are explained below:
Using inline tags in the translation
When translating XLIFF files, the inline tags contained in the source document must also be inserted in the translation. Normally, each inline tag can only be used once in the translation (exception: see "cloneable elements" below). The tags must be used at the right position and in the correct order (e.g. start tag first, then end tag). The easiest way to do this is to move the cursor to the position at which the tag is to be inserted and then to double-click the respective tag in the source segment. Alternatively, this can be done with keyboard shortcuts: For example, press Ctrl+Shift+1 to insert the first tag from the current source segment in the translation, Ctrl+Shift+2 for the second tag, and so on. Press Ctrl+Shift+0 to insert the current tag in the translation.
Cloneable elements are special inline elements that—unlike normal inline elements—can be inserted several times in the translation, e.g. to mark up an additional word in the translation. Cloneable elements resemble normal inline elements, but are orange (instead of gray). The procedure for using cloneable elements in the translation is the same as for normal inline tags (see above).
Paired elements are special inline elements with the designations bpt (begin paired tag) and ept (end paired tag), which always occur in pairs in a translation unit. During the translation, paired elements are displayed and processed like normal tags; the only difference is that the bpt tag, i.e. the start tag of the paired element, must be closed with the corresponding ept tag, i.e. the end tag (not with an end tag of the same name as usual).
Note: XLIFF files may be bilingual; apart from the source-language segments, they may already contain translations. In this case, the respective segments will have the special editing state "Touched (inserted from bilingual document)" or "Translated (inserted from bilingual document") in the crossDesk translation editor.
Tips and Tricks
The Across Translator Edition features special quality management criteria for the translation of XLIFF files. These criteria help to avoid errors, especially in connection with the use of inline elements in the translation.
XLIFF element validation
Checks whether the inline elements including the cloneable and paired elements (see above) have been inserted correctly in the translation.
Checks whether the number of inline elements is identical in the source and target segments.
Checks whether the inline elements that occur in the source segment have been used in the correct order and number in the target segment.
Creation of special settings templates
If you frequently need to translate XLIFF files that differ in terms of their bilingual content (see information on "bilingual XLIFF files" above), you may want to create two separate document settings templates (under >>Tools >>System Settings ... >>Document Settings >>XLIFF): one for conventional bilingual XLIFF files and another one for bilingual XLIFF files whose target-language content is to be ignored.