SET REFERENCE USEVIEWFLAGS

I am trying to utilise a key-in on a batch of files to make sure the references have the Level Overrides flag on. It should be easy enough, using SET REFERENCE USEVIEWFLAGS <setting_spec> <file_spec> but it isn't...

The Setting Spec should use the same values as MS_REF_DEFAULTSETTINGS, but that doesn't appear to have a setting for level overrides.

What would the correct keyin be to do this for all reference attachments? ie SET REFERENCE USEVIEWFLAGS what?=1 *

Thanks