Complex sentence: To make katakana fit into the area allowed, some compromises were made: the diacritical marks Dakuten and Handakuten are treated as separate characters instead of being part of the preceding character.
Split into simpler sentences: To make katakana fit into the area allowed, some compromises were made. For example, the diacritical marks "dakuten" and "handakuten" are treated as separate characters instead of being part of the preceding character.