Currently, we have two options when we want to instruct CAESAR to ignore stresses for any given portion of the model:
1) set the allowables to 0
2) set up a user defined material, where we leave allowables to 0, but fill out the rest of the information (thermal expansion, etc) manually.

It would be more straight forward if we could just change the "code" to "none" as it's only one input.

This would be better as future revisions of the model may make it easier to miss these manual changes.