I am sure you are right as the code for Michel Adam roses is usually ADA. However the American Rose Society Modern Roses data base is showing ADharman. We'll make enquiries.
Even more puzzling is the code that Tasman Roses in New Zealand are showing for the same rose, 'Lasting Love'. (ADAbreton)
Nope. It was registerd as Adharman. Actually, there have been other Michel Adam code names which have not followed the ADA format, such as Adecosil, Adecorhuit, Adecohuit, Adecapma, Adesmanod, and Adharos.
The Approved Exhibition Name has been changed now to Lasting Love. I exhibited this rose today at an ARS show under the name Commandant Cousteau and it was DQ'd for being misnamed.