How to identify or distinguish the "system-administrators" group from other user-created groups?

[Leo Nguyen]

I have a question about the built-in group system-administrators.
When retrieving groups through the API (for example, /rest/api/3/group or /rest/api/3/groups/picker), this group appears the same as other user-created groups — there doesn’t seem to be any specific flag or property that indicates it’s a system or default group.

Question:
Is there any attribute, flag, or API field that can be used to identify system groups like system-administrators, site-admins, etc., to distinguish them from normal custom groups?

If not, is there any recommended best practice for recognizing these groups programmatically?

Thanks in advance for your help!

[marc -Collabello--Phase Locked-]

As far as I know, there is no way to distinguish them except by name.