P: Face tagging with Parent > Child keyword notation causes errors
You can't use the Parent > Child keyword notation when tagging faces -- LR will rename the child keyword to be a screwy name, and it can cause an internal error.
To reproduce:
1. Create two parent keywords, Friends and Family.
2. Under each of those keywords, create the child keywords Peter and assign each Peter to a separate photo. The hierarchy now looks like:
3. Go to a photo with no keywords, draw a face rectangle, and enter "Family > Peter" into the person box.
4. LR incorrectly renames the keyword Family > Peter to be Family > "Family > Peter":
Sometimes this can result in a LR internal error, "name is not unique", though I haven't been able to reproduce the exact steps for this to happen: 
