Translation updates for documentation are handled through a script called doc-check. Although the tool shares a common name, different documents use a different version (or incarnation) of the same tool (or concept). Basically, the translators need to add to each translated file a translation header that specifies which file revision was translated. So, if a document was translated based on the 1.12 revision in CVS, a translator would add this header:
The specific header format used might vary between documents, for example, this is the translation header for the translation of a file in the Debian Installation Guide:
If these headers are in place a translator can use the doc-check tool to:
show which translated files have a different revision number from the original English files
show what changes have been made in the original English file
help keep track of which files have not yet been translated
In order to use the tool the translator just needs to update his/her local copy of the document source code, run the script and review the output. The use of a revision control system helps the translator extract[1] which changes have been introduced in the translated file. (S)he can then update the file, update the translation header and commit his/her changes.
This mechanism is indeed very similar (if not the same) to the mechanism used in the website to manage translations.
Translations that feel more comfortable using PO files can use either po4a (see Section 4.3.2), or poxml. The Debian Installer uses poxml and provides tools to convert from the XML files to PO files for the translation teams interested. A different set of tools converts the PO files back into XML files. "Out of dateness" of translations is handled through the same PO mechanisms (fuzzy) as those used by gettext to determine whether to show a translated message or not.
| [1] | The doc-check script of the d-i project can extract the changes between revisions by making the proper queries to the revision control system if asked to. |