What does the # symbol mean on facebook?

[Christi Oakltree]

Could be a hash tag symbol
people tag things to give their words a basic category #confusion

[Evolving Squid]

It means someone is trying to draw undue attention to something they wrote.

It is worth noting that on Twitter, where hashtags started, there is no difference between #whatever and whatever... there is nothing special about a hash-tag as you can search on any word.

[Peanut]

Are you sure it s on Facebook, cause i ve never seen it used there before. Now, as far as Twitter is concerned, it means hashtag. sorry to not be of any help

[Jon Gould]

it means search for whatever follows the # when used in the search box