Dear Ms. Mather,

The abbreviation 'PT' refers to Physical Therapy of Physical Therapist.

'AT' or 'ATC' would indicate an athletic trainer or certified athletic trainer.

This may seem inconsequential to you, but as a Physical Therapist I do not want to be mistaken for a personal trainer.

Thank you,
Barbara L. Goldstein, PT

https://www.yahoo.com/news/woman-shares-her-embarrassing-moment-144238418.html