Do all Dior handbags have a date code on the tag?

My nan has given me a small Lady Dior handbag and although everything else is perfect in the making of it, there is no code on the back of the tag it only says made in Italy. I read that before 1999 they didn't have the codes is this correct? Or do you know of anywhere I could find out? Please help!|||i don't know I think you search this site