Multiple attributes associated to a skill?

[ShadowWalker]

I'm trying to create a system where the skills have three attributes associated with the skill and the attributes could be duplicated.
So a skill could have STR, DEX, DEX, or even DEX, DEX, DEX.
Using linkage won't work as you can only have one.
Tags you can only have one of each.
I thought maybe tags saying STR1, DEX2 or DEX3 for the above examples.

Any suggestions on what would be the best way to do this?

I have something similar to do with occupations. They have skills associated with them and a starting value for that skill. Not sure how to associate a value to a skill within the occupation.