Re: [EXT] Legal characters in id name

Frank da Cruz wrote: (Last Updated 26 February 2021) says:

"The id attribute specifies its element's unique identifier (ID). There are no other restrictions on what form an ID can take; in particular, IDs can consist of just digits, start with a digit, start with an underscore, consist of just punctuation, etc.  An element's unique identifier can be used for a variety of purposes, most notably as a way to link to specific parts of a document using fragments, as a way to target an element when scripting, and as a way to style a specific element from CSS."

The HTML5 validator accepts id="[-123-]" but not href="#[-123-]":

"Bad value #[-13-] for attribute href on element a: Illegal character in fragment: [ is not allowed."

But clicking on the link works.

Many things work, Frank.  However, the validator is not defined in terms of what works (in a particular browser, under a particular operating system, when the moon is in a particular house, and so on) but rather in terms of what is stated in the corresponding specification.  Note in particular :

The href attribute on a<> and area<> elements must have a value that is a valid URL potentially surrounded by spaces<>.

A quick look at the value you are ascribing to your HREF indicates that you are trying to include square brackets.  The specification<> says :

A host identified by an Internet Protocol literal address, version 6 [RFC3513] or later, is distinguished by enclosing the IP literal within square brackets ("[" and "]"). This is the only place where square bracket characters are allowed in the URI syntax.

Therefore, in order to be compliant, you will need to URL-encode your square brackets.
Philip Taylor

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Received on Saturday, 27 February 2021 15:23:26 UTC