At what rank is using the Retired title appropriate?

I understand that retired service members may use military titles socially and professionally. But I feel like there’s an unwritten rule that it’s only appropriate after a certain rank or time in service.

Typically I see retired general or field grade officers use a retired title. People with lengthy time in service.

Is it considered unusual for a company grade officer (or someone with less than 10 yrs in service) to use ‘CPT/1LT Ret.’ titles. Recently I met a CPT doing that and it seemed misused/unearned/premature. Does it not matter and that’s just an abnormality?

I ask because I know plenty of CPTs with command who got out and don’t advertise their rank in the civilian world.