Naming a space that contains equipment requiring servicing something other than utility room...
Which makes an attic a "utility room"? Language doesn't work that that way. The way the section is worded starts with specific locations (
For attics and underfloor spaces, utility rooms, and basements,), then says this section is about only them (
where these spaces) excluding any other unmentioned spaces, then further sets a condition on how they're being used (
used for storage or contain equipment requiring servicing).
Or- (3) applies when you have storage/equipment and the space is already considered an attic/basement/utility room.
If an attic or basement isn't being used for storage and has no serviceable equipment, it doesn't need a light. If an underfloor space, not matter how small, is used for storage, it does need one. A kitchen with the water heater in the corner doesn't need a light per (3) because it's not a attic/basement/etc; OTOH it does because covered by (1).
In the room. I could never image a design where I would rely on lighting from an adjacent space.
The light at the top of a 3' square closet isn't going to help with servicing the front of a water heater. And calling a 3' square space a room is really stretching the definition, most people would call it a closet.
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