Is there another word for the number sign " # " ?

[Rosey G]

I read where some UK speakers use Hash. Does anyone have an idea or heard of it?

Thank you in advance for your answer.

[JuanB]

hash or hash mark - as used for hashtag in twitter
pound key on the phone

[you, me and kinect]

Yeah, its called a hash/hashtag

[John G]

I worked in IT in the UK in the 60s and its always been called a hash in the UK, it wasn't used as a number key, it was often used to comment out words in programming languages back then.

[teeny-tinyPupil566]

I believe that the long standing name of this symbol is
'cross hatch'