The bulk update request #6 is active.

create alias outdoor (70) -> outside (13925)
create alias outdoors (21) -> outside (13925)

Reason: Both of those are aliases of outside on e621, and... well, they all mean the same thing. Don't think there's a reason to keep them separate.

EDIT: The bulk update request #6 (forum #244) has been approved by @Dasadevil.

Replying since still "pending approval".
At e621, outdoor and outdoors both alias to outside. ( https://e621.net/wiki_pages/1815 )

At e6ai:
outside with 5903 posts.
outdoor with 146 posts.
outdoors with 2174 posts.

Although I'm not a native speaker, the way I understand it is that "outside" means anything outside a building or natural shelter, whereas outdoors has a bias towards nature, countryside etc.

You don't say "outside sports" but "outdoor sports", for example.
I'd rather say that outdoors should imply outside. I wouldn't tag a picture in the city streets as outdoors, but I would do so for a hiker in the hills or forest, and maybe a jogger in a park.

The bulk update request #6 (forum #244) has been approved by @Dasadevil.