Complex sentence: The second law on the use of languages (1878) regulated the use of language in the administrations of Flanders and Brussels, announcements to the public by government officials having to be made either in Dutch or in both languages.
Split into simpler sentences: The second law on the use of languages in 1878 regulated the use of language in the administrations of Flanders and Brussels. Announcements to the public by government officials had to be made in either Dutch or in both languages.