HTML5 Compliant - Trailing Space in Class Attribute

Question

I know that technically HTML5 is a \'living spec\' but I\'m wondering if it\'s compliant to have trailing spaces inside of a class name. I didn\'t see any reference to this

Answer 1

As we can see in the link below, there is no restriction on what the developer can use in the class attribute.

http://www.w3.org/html/wg/drafts/html/master/dom.html#classes

In fact, after saying what the classes are and that they're used spliting in the spaces, the author(s) says:

There are no additional restrictions on the tokens authors can use in the class attribute, but authors are encouraged to use values that describe the nature of the content, rather than values that describe the desired presentation of the content.

Our colleagues here have tested and it successfully passes W3C validation, so I can't guess why your friend thought it was invalid.