What's the HTML character entity for the # sign? I've looked around for "pound" (keeps returning the currency), and "hash" and "number", but what I try doesn't seem to turn into the right character.
You can search it on the individual character at fileformat.info. Enter # as search string and the 1st hit will lead you to U+0023. Scroll a bit down to the 2nd table, Encodings, you'll see under each the following entries:
HTML Entity (decimal) # HTML Entity (hex) #
The "#" -- like most Unicode characters -- has no particular name assigned to it in the W3 list of "Character entity references" http://www.w3.org/TR/html4/sgml/entities.html . So in HTML it is either represented by itself as "#" or a numeric character entity "#" or "#" (without quotes), as described in "HTML Document Representation" http://www.w3.org/TR/html4/charset.html .
Alas, all three of these are useless for escaping it in a URL. To transmit a "#" character to the web server in a URL, you want to use "URL encoding" aka "percent encoding" as described in RFC 3986, and replace each "#" with a "%23" (without quotes).
For # we have #.
Bear in mind, though, it is a new entity (IE9 can't recognize it, for instance). For wide support, you'll have to resort, as said by others, the numerical references # and, in hex, #.
If you need to find out others, there are some very useful tools around.
# or #
http://www.asciitable.com/ has information. Wikipedia also has pages for most unicode characters.
There is no HTML character entity for the # character, as the character has no special meaning in HTML.
You have to use a character code entity like # if you wish to HTML encode it for some reason.
The numerical reference is #.
# is the best option because it is the only one that doesn't include the # (hash) in it. Supported by old browsers or not, it is the best practice going forward.
(What is the point of encoding something using the same symbol you are encoding?)
来源：https://stackoverflow.com/questions/3025171/whats-the-html-character-entity-for-the-sign