Name of the room + number.
I’ll give the human readable name a bit more info like if it’s a fan (then it’s ‘Kitchen Fan 1’, ‘Kitchen Fan 2’, etc…), but I’ll usually make a group and expose the group to voice and the group would be based on the human name (Kitchen Fan). For most rooms though, I only really care about the room itself, so, “turn off the kitchen lights” is all that’s really needed and that’s handled by the zones.
On KBin I believe that it is (or at least was a bug that became a feature). There have been posts about it strongly urging Ernest not to change it and he’s said he’ll open it up to discussion before making major changes to it, if my recollection is accurate.