LibreOffice has no spellcheck dictionary for belorussian language, but exists spell dictionary for belorussian. Site spell-be.sf.net But its License: Creative Commons Attribution-ShareAlike It works well. But I do not know if this compatible with LGPLv3 or not. If compatible, then it can be included into LibreOffice. Citation from other bug 34910 I am not 100% sure but I think that it could be included. Dictionaries do not include executable code, so there are less strict rules for the compatibility of licenses. Anyway, please open separate bug for adding the dictionary and mark it as enhancement. Let's leave this bug for the generic problem that affects all dictionaries.
I take this.
Pushed to master (-> LibreOffice 3.5)
Thanks