Again, what I know, I think everyone else knows. In this case, a question on the forum raised my level of awareness of things that I take for granted.
A question was asked how to change table values, where to look at what is there, and how to change them.
I will start by looking at the ORM_O01 message and we are going to be looking at the Gender element (yes I could use the real word, but I don't want to end up on a blocked site list!)
By clicking on the PID_8 in the properties you see the information you need in the Base Data Type
So we go to the tablevalues_{version}.xsd and look for that table (fortunately we only have to look at the first one!) and click on Enumeration:
Now you can add/remove the values that you need.
Note: The thing you need to make sure is that you will need to redeploy all of the schemas to make it work again.