URL-ENCODING
URL-ENCODING, also known as PERCENT-ENCODING, is a mechanism for encoding information in a URI (Uniform Resource Identifier). This process is necessary because URLs can only be transmitted over the INTERNET using the ASCII character set. Since URLs often contain characters outside the ASCII set, they must be converted into a valid format. The encoding consists of a percent sign followed by the two-hexadecimal digit representation of the character's byte value.
The technical specifications for URL-ENCODING are primarily defined in RFC-3986. According to this standard, characters are divided into reserved and unreserved categories. Reserved characters, such as the colon (:), forward slash (/), and ampersand (&), have special meanings within the context of a URI. If these characters are used as part of the actual data, such as within a QUERY-STRING, they must be encoded to prevent the WEB-BROWSER or SERVER from misinterpreting them as delimiters.
Common examples of encoding include the space character, which is represented as %20, and the exclamation mark, which becomes %21. Modern implementations often use UTF-8 character encoding before converting the bytes to hexadecimal triplets. For further information on implementation details, you can consult the MDN Web Docs on Percent-encoding or read the full RFC 3986 specification via the IETF.