Many of the translations are outdated due to the fast evolving of the code.
Any contribution to the translations is welcome.
Just edit the to the language corresponding ".po" file in the cps/translations folder (up to the line: "#. name for aaa", approx line 1900) and create a PR request. I will include it to calibre Web.
(Editing this file will not make the text instantly translated in Calibre Web, they have to be compiled first with poedit, pyBabel, or something else...)