Board Thread:Support Requests - Designing Your Wiki/@comment-33039081-20190813185003/@comment-366087-20190813190628

Sure. Narrow-niche wikis, such as, for example, Our Neighborhood Stickball League is acceptable so long as it also follows the Community Creation Policy. Especially the part about Public Editing.

Mainly, you want to avoid For Profit Businesses to minimize being seen as a source of spam.