URL encoding converts characters into a format that can be transmitted over the Internet.
There are times when developing in ServiceNow you need to encode/decode characters depending on the situation. Here is a cheatsheet to help.
%20 (blank)
%21 !
%22 "
%23 #
%24 $
%25 %
%26 &
%27 '
%28 (
%29 )
%2a *
%2b +
%2c ,
%2d -
%2e .
%2f /
%3a :
%3b ;
%3c <
%3d =
%3e >
%3f ?
%40 @
%5b [
%5c \
%5d ]
%5e ^
%5f _
%60 `
%7b {
%7c |
%7d }
%7e ~