Re: It's deja-vu all over again ...
Oh God, yes, this!
Client: We didn't want to disturb you by asking for a new custom field so we put the customer's ebay reference number in the phone number field as ebay won't tell us the phone number on orders so it didn't matter.
Client later on: How many of our customers are ebay customers?
Me: Dunno, I could have told you if you'd let me spend all of 5 minutes putting in a custom ebay reference number in the first place and not used the phone field.
Client: Erm, can you separate them out?
Me: Possibly. It will take a while as I've got to write a program to figure out how to tell the difference between the two...
Me a short while later: What are these types of entries? They match neither a phone number format nor an ebay ID.
Client: Oh, they're Amazon reference numbers - we, er, didn't want to bother you...
Me: AAARRRRGHH!!!!