Re: [EXT] Legal characters in id name

Frank da Cruz wrote:
https://html.spec.whatwg.org/multipage/dom.html#the-id-attribute (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<https://www.w3.org/TR/html52/single-page.html#elementdef-a> and area<https://www.w3.org/TR/html52/single-page.html#elementdef-area> elements must have a value that is a valid URL potentially surrounded by spaces<https://www.w3.org/TR/html52/single-page.html#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<http://www.ietf.org/rfc/rfc3986.txt> 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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