HTML URL codes Info

Answers to link and URL encoding and decoding plus dereferring

Important: In reference to URL codes, the terms "link" (Hyperlink) and "URL" (Uniform Resource Locators) means the part to the right of a domain.

URL codes are only needed to the right of a domain.
https://www.example.com/                    Path outside of domain URL                    
A path points to the resource of a document (html, php, pdf, ...).
For domains is this regulated with punycode. (www.québec.ca → www.xn--qubec-csa.ca)
Note: Some websites hide the part "index.html" or "index.php" (homepage).

In particular, URL codes are needed mainly in URL Query strings.
https://www.example.com/blog/index.php?=                    URL Query string                    
A URL query string sends additional information to the server.
Note: Some websites hide the part "index.php" (homepage).

Rarely, but also, URL codes are required when sending URL fragments to a server.
https://www.example.com/blog/index.html#                    URL fragment                    
A URL fragment points to locations within a loaded webpage.
Note: Some websites hide the part "index.html" (homepage).

The characters outside of the secure and unreserved ASCII Unicode block for links and URLs are encoded into a secure format to transmit the information they contain. This usually happens unnoticed inside the internet browser. A user only notices this if he wants to copy a link or URL directly from the address bar of the browser or with the bowsers context menu from a webpage into the clipboard of his computer and then insert it somewhere. Then the link or URL is encoded. Links and URLs can only be transmitted on the Internet with the unreserved ASCII characters and the URL codes. Unreserved ASCII characters and other characters in links and URLs are lost on the Internet. The links and URLs then lead to a wrong destination. This does not happen with links and URLs in browsers, as they automatically encode the links and URLs. Some email providers encode links and URLs in emails repeatedly and excessively. This is not a security measure, but a spleen of the email provider to prevent copy & paste. Repeatedly and excessively encoded links and URLs do not work when copying and pasting. Encoded links and URLs are not human readable when copying and pasting it. This should complicate the copy and paste. In addition, some e-mail providers add a Dereferrer to links and URLs in emails to mask their own information retrieval and deleted the Session-ID in the URL so that the email account can not be hacked. You can truncate the Dereferrer after copy & paste it. After copying a link or URL from a webmail, the Dereferrer is no longer needed when the link or URL is called outside the webmail web page. Decoded links and URLs work in browsers, because they are encoded by those before being transmitted to the Internet.