Nesting catgryGrps - use "catGrp"
catgryGrps can be nested inside each other! It's neat! You do this by listing another catgryGrp as one of the component parts of the catgryGrp that includes it.
However, I've noticed a mistake that's in a few older files . . . I don't know how pervasive it is.
This is the mistake:
<catgryGrp ID="CVG1_1" catgryGrp="CVG1_2 CVG1_3" catgry="CV1_5 CV1_6 CV1_7">
This is how it should look:
<catgryGrp ID="CVG1_1" catGrp="CVG1_2 CVG1_3" catgry="CV1_5 CV1_6 CV1_7">
The subtle nuance is that you need to use "catGrp", not "catgryGrp"