itum seems like it should be spelled item - need a comment

[schwehr]

If it really should be itum, what does it mean? This is short for Id To Unit Map, yes? Perhaps a comment somewhere?

find . -name "*.[ch]" | xargs grep -i itum

./lib/ut_free_system.c:	itumFreeSystem(system);
./lib/idToUnitMap.h:itumFreeSystem(
./lib/idToUnitMap.c:itumNew(
./lib/idToUnitMap.c:itumFree(
./lib/idToUnitMap.c:itumAdd(
./lib/idToUnitMap.c:itumRemove(
./lib/idToUnitMap.c:itumFind(
./lib/idToUnitMap.c:		    *idToUnit = itumNew(compare);
./lib/idToUnitMap.c:		    status = itumAdd(*idToUnit, id, unit);
./lib/idToUnitMap.c:		: itumRemove(*idToUnit, id);
./lib/idToUnitMap.c:	    const UnitAndId*	uai = itumFind(*idToUnit, id);
./lib/idToUnitMap.c:itumFreeSystem(
./lib/idToUnitMap.c:		    itumFree(*idToUnit);