I was reading a post by Brian Renehan @ Revit Fix about changing parameters that are in the out-of-the-box families. As I previously posted, you don't have to go through these steps to change from Type to Instance...there is a check box you can use in the Options Bar.
This got me thinking and testing as well...since you can modify one of these "system" parameters based on Brian's post, what happens if you try to delete or modify the name. Well, here's what I found...
The image below is what I did when I changed the Category to Generic Model and modified the Height Parameter. I changed it to say "Height Test", made it Instance Based and changed the parameter category to Other.
Then, I changed the Family Category back to Casework and took a look at the parameters again. Interestingly the Height parameter came back... as a Type Parameter and without a Value. The Height parameter that I had modified was still present with the changes that I made, and was the parameter that was being used for the dimension label.
So the parameters that you see in the templates are really built into the programming of the family category. If you really want to see what parameters are built into a family, start a family as a Generic family and then change it to another Category. The Generic family basically only consists of the parameters in Identity Data and when you change it to another Category, the parameters built in will appear.