Proper installation of a toilet flange?

As a DIY person, I have a question about the proper installation of a toilet flange. The plan for my renovated bathroom is to tile the floor but I need to know if the toilet flange should be attached to the subfloor (and so the top of the flange would be level with the top of the tile) or should I tile the floor and have the flange sit on top of the finished floor?
I've been on the internet searching this and it seems there are many proponents that say the flange should sit on top of the finished floor. However, I have heard the top of the flange should be flush with the finished floor (i.e. attach the flange to the subfloor and tile up to it). Is this not covered in the National Building Code etc. so we can determine one correct way of doing it?
Thanks for your help.

Regards,
Ray

If this forum had a FAQ page, this would be on the top of the list. I'm glad you asked the question before proceeding and doing it wrong. The flange is attached to the drain so that it rests on top of the finished floor. It then needs to be screwed through the finished floor and into the sub floor. If the finished floor is tile, you may want to notch the tiles when laying them to accommodate the screws as drill holes can be difficult. I would suggest using several #12 stainless steel screws to insure they will not rust out. Since the flange needs to rest on top of the finished floor, you may want to wait until the flooring is laid before cutting the drain pipe to length so the fit will be right. Certainly make sure the flange sets level on the floor so that the toilet will seat properly.