Unique Group ID

[Sevisin]

Hello,

I hope I'm in the right forum. I'm looking to create a custom feat that requires a drop down list (like Weapon Focus) of a list of custom abilities. Maybe it's because it's almost 2am, but I can't figure out how to make a unique/custom Group ID. When I put "Abcd" in "Group ID" in the Tags menu, it gives me the error "File....... - Thing 'cDK_03' (dynamic tag) - Group 'Abcd' not defined."

Maybe a good night's rest will help, but any thoughts or ideas will help. Thanks.