>I understand what you're saying - I may just consider that, there won't be a limit of 5 in that case.

Furthermore, you wouldn't be wasting space for cases where you need only one. Actually, at that point you really don't care how many you have, zero to n is acceptable.
Another maintainance nightmare also solves itself - when, along with the reference, you need additional things about the reference (good candidates are type of reference, source, any imaginable date etc etc) that you would have to add five times (and do hell of a lot of typing in any SQL statement where it may apply, and you may discover you have dozens of those).

I've had a thing like that here, for a series of meetings or other events I had eventtype1, contact1, time1, eventtype2, contact2, time2, eventtype3, contact3, time3,... and it went all the way to 7! (No, not me, this is inheritance... from previous programmers). Now imagine if somebody wanted to add location - it would take seven additional fields, which would then add a bunch to each of the fifteen SQLs which were already couple of kilobytes long....