Had a look at this post but it doesn't tell me what I need:
I want to create a farm level UDA and control permissions to it to only allow users of certain AD groups to actually be able to use the UDA. I was hoping I could manage the UDA in a similar way to the "Manage Allowed Actions" section in central admin. calling you out as you replied on the above post.
Is it possible to say who can and who cannot use a farm level UDA?