Custom Tag Security - Default Access Setting

Hello All,

Was wondering if there is a way to define a default security policy on tags with custom security enabled – e.g. if the current user does not mach any of the roles defined in the “custom permissions” table:

Doesn’t seem like the table accepts “null” as a roll (would have assumed this would match “everyone” like how we define security for designer access, client launch, etc…)

Thanks in advance!