Complex sentence: Through the language selector of the site, it is possible to switch between 699 languages, although about a hundred languages are restricted to "publication download only" (not the website language) and another eighty languages are sign languages.
Split into simpler sentences: Through the language selector of the site, it is possible to choose between about 700 languages. Inlcuding about a hundred languages which are not the website language, but "publication download only", and another eighty languages are sign languages.