That wouldn't fly here (Maryland, USA). To be listed as a bedroom, it must be finished, have a closet, and a second exit like a window or another door, so that you could get out in case of fire.
One house we looked at had a bathroom that was so narrow you had to turn to the side to enter. I think that was the same house that had some light switches that were at knee-height.
One of the things that really drove me crazy when we were looking for a house -- the listings that said the house had four bedrooms but only had three -- maybe these 4th bedrooms were all secret rooms!
My friend bought a house that was listed as a 4-bedroom. Two of those were upstairs, one was the pantry (with no door) and the other was the basement
I know bedrooms don't have to have closets here (our place right now has three bedrooms, and one closet), but the window is a must. The pantry did have a small window at the end, and there were also windows in the basement, so I guess that qualified. But it's kind of like someone putting out a personal ad claiming to be 6'5 and athletic when they're actually 4'2 and a marshmallow; do they think no one would notice that the realtor thinks they wouldn't mind sleeping in the kitchen?
It's pretty funny, what they thing they can get away with. We had a giant pantry at our old apartment, and even then, I don't think you could make a bedroom out of it. I did know a guy who had a "1 bedroom" apartment that was a living room, with a closet exactly the size of a twin bed, with about two feet of space at the end of the bed to allow you to reach the bathroom, which was supposedly the bedroom.
We saw one house that had odd closets jutting out into the room, and the realtor told us that it was because somewhere along the line, someone was under the impression that you needed closets for it to officially be a bedroom, so they just tacked some on.