[veltas]

A 'hash-tag' is a feature of internet apps like Twitter where you put a '#' in front of some topic name to relate your content with similar content. It's named after the character which is known as a 'hash' among other things.

Or are you saying 'hash-tag' is the name because although it's a mistake it's used so much now it's considered language?

Language isn't one big blob, even though among many people it could now be considered an alternative pronunciation, and eventually it could be adopted even in places where people would otherwise know better, right now among people in tech and certainly on this site 'hash-tag' to mean the character is incorrect and confusing.

[hackerbabz]

But there isn’t another character that anyone calls “hashtag”. It’s like if everyone nontech called “:” a “semicolon” only when it’s preceeded by “http”. There is something else called semicolon and its not the thing in the url.