How did he know that I am Protestant?

My mom was hospitalized for almost a month at Mercy Medical Center. Although she had recovered from her condition, she was unable to stand up on her own because she had been in bed for the whole month. They provided a week of physical therapy at the hospital, but she needed extended in-patient physical therapy. Prior to her release, I visited several of rehab/nursing care facilities in the Baltimore area.

One of the best rehab/nursing care facilities in the area is St. Elizabeth. When I paid a visit to the facility, the admission director said something that... well... Let me just describe what happened.

As he showed me various aspects of the facility, he rattled on about things of which he was obviously very proud.

At one point, he said looked at me, and said, "Oh, and we don't just serve Catholics; we care for Protestants, too... as well as non-believers and believers of other faith."

It was almost as if he was saying, "We know that you are Protestant but that's OK."

How did he know that I was Protestant? Are there external features by which he could tell if one is Catholic or Protestant? Do Catholics and Protestants have their own Catholic and Protestant English dialect? Do they have their own distinct fashion style?

I don't know; I'm not Catholic. For all I know, he may be expecting a password from Catholics.