Complex sentence: Traditionally, the names of all halogens end in "-ine"; however, the IUPAC guidelines valid at the moment of the discovery approval required that "all" new elements be named with the ending "-ium".
Split into simpler sentences: Traditionally, the names of all halogens end in "-ine". The IUPAC guidelines valid at the moment of the discovery approval however required "all" new elements be named with the ending "-ium".