URL encoding specific for encoding some characters in a URL by replacing them with one or more characters, that consist of the percent character (%) followed by two hexadecimal digits.
Reserved characters:
([ ] ! * ' ( ) ; : @ & = + $ , / ? % #)
Unreserved characters:
(A to Z), (a to z), and (0 1 2 3 4 5 6 7 8 9 - _ . ~)
See Also