// traverse the visit file, checking each record against those two lists and
// purging the ones that do not have a match on _both_ lists. (Remember, if
// either the room or user being referred to is no longer on the system, the
// traverse the visit file, checking each record against those two lists and
// purging the ones that do not have a match on _both_ lists. (Remember, if
// either the room or user being referred to is no longer on the system, the