I use a back stamp that has blanks for the date the negative was made, and the date I printed it. When I used to date the front (I later decided it wasn't needed) I would just write the year of printing.
It's my opinion that the information of provenance does not need to be displayed on the face with the print, and a signature on the front is all that most people want.
That said, I have seen about as many different ways as I have seen photographs. I would love to know if there is a method that is favored by the market.