What programming language are the % characters in URLs?

Question

Just curious what language these characters in a URL are from?

For example:force_name=1&name=Tom%20 which is a space.

Answer 1

The % characters in URLs are not a "programming language." Rather they are URL Encoding or just Percent Encoding. They allow characters to be used in URLs that that cannot otherwise be used un-escaped.

%20 is a space because 20 is the ASCII code for a space character. A space cannot be used in a URL un-escaped because not one of the characters listed as being allowed in URLs.

Percent encoding is defined in section 2.1 of RFC 3986: Uniform Resource Identifier (URI): Generic Syntax.