Marking silicone molds

I've got a question for anyone who is doing their own casting and have been doing it for a while.

Do you have any tips or tricks for marking existing molds?

I wish there was some easy way to, for example, make a mark every time a mold is used to keep track on wear. Or make a mark once a mold is nearing the end of it's life so I know what to expect.
I've tried a number of different types of pens and paints, but not surprisingly, none of that sticks. Only one thing sticks to silicone, after all. I have tried to make small cuts or gouges on the outside, but it's very dificult to see and ricky to do on small molds.

When I just started out and had just a handful molds for a single doll and a few extra parts this was not a problem as I could keep track in my head, but now several projects and many years later, that is no longer possible.
I do keep the molds for different dolls apart by colour coding the silicone and that helps a little bit. And making a number or other mark right when making the mold is possible. What I need is a way to mark it later.

How do you guys deal with it? Simply staying super organized? Moldnumbers and charts? Some type of dye/ink/paint that I am unaware of?
Tell me your secrets!

Thank you!

 

@c4tbus
Thank you! That could probably work well for those semi-retiered molds that still may have a few good casts left to them.

It's probably a bit too invovled to use as a routine marking for every cast, but for important notes it has potential. I will try it!