In the plugin listing labels you have the option of verified by photo, where the user can validate the ad, sending a photo holding a paper with the name of the website and the date of the day.

Please, when the ad is verified, how can I remove the verified stamp from an ad? and it remains active without the stamp?

The status of the verification request is VERIFIED and cannot be changed, and also in the listing you do not have this option.

** The ideal is for the seller to be verified and not the ad, otherwise he will have to validate each time he makes an ad.

Best regards