A full bathroom includes four components: bathtub, shower, sink, toilet. A half bathroom is just a sink and toilet. A 3/4 bath is a bathroom without a bathtub. It's very common in shitty apartments.
How common is this? I’ve never seen a bathroom with a stand up shower listed as 0.75 bathrooms. Were they all supposed to have been listed that way, or is it regional?
All three times I've purchased or sold a house in New Mexico this is standard practice. I never directly asked, but when listing it sounded like bathrooms without a bathtub weren't allowed to be entered into MLS (the national realtor database) as a full bath.
How interesting. I've never encountered it in NY, but I found this site[0] which suggests that what you're describing is how it should be listed.
It would likely turn into a huge mess here if they started enforcing this. A house I previously owned would be reduced from 2.0 bathrooms to 1.75 bathrooms.
3/4 bathrooms are quite common in some places, but listings may be not obvious because if you have 2 of those you will see 1.5 bathrooms and believe there is 1 + 1/2, not 2 x 3/4. My place has such an arrangement, I don't like bathtubs and I find it perfect for me.
I've never seen that either. And it's very common. Hardly just "shitty apartments." In fact, when I had my bathroom remodeled a few years back, I changed it from having a bathtub/shower to just a shower.