What is Ad-hoc?



I have been through lots of posts (like: TABLET - Editorial, TYPING - Editorial), with a tag ‘Ad-hoc’ pinned to them. What does that mean at all?

The literal meaning according to Google is ‘when necessary or needed’, but I think it don’t that helps here.

Thanks for helping me geeks!

EDIT: BTW, what is community wiki?


Why don’t they just use ‘none’?


Thanks anyway!