What happens to my O-A visa if I leave Thailand and return after its expiry with a re-entry permit?

The O-A multiple entry visa is valid for entries until the specified expiry date, which the user understands may be affected by leaving the country. If a re-entry permit is obtained before leaving, it allows the user to retain their current 'admitted until' expiration date as long as they return before that date. However, if the user leaves Thailand and does not return until after the original visa expiration date, they will need to apply for a new visa. The overall advice suggests that if intending to leave, securing an extension prior to departure is advisable.