BUR #27318 has been approved by @nonamethanks.
nuke skylight
create alias skylight_(architecture) -> skylight
remove alias skylight_(architecture) -> skylight
A tag for "light coming from the sky" is essentially just a parent tag for sunlight and moonlight, with a few other things in the middle. Even if someone did want to search for this (for whatever reason), such a tag would be 95% made up of sunlight posts due to its comparably vast count.
However, someone made it anyway, and for whatever reason, they called it skylight. This is why skylight_(architecture) has a qualifier, as it was made later.
Outside of Danbooru, "skylight" unambiguously refers to windows installed in or as the ceiling. In fact, it's so unambiguous that if you search Google Images for it, that's all you'll find. Indeed, even many of our users just assumed the skylight tag was for ceiling windows; I fixed forty-odd mistags where skylights were, completely understandably, tagged as skylight.
I think we can safely repurpose skylight for actual skylights without worrying about mistags when that's already what people assume it's for.