/ 
HTML-Lint-2.32
River stage two • 17 direct dependents • 35 total dependents
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/ t/strong-id.t 
HTML::Lint 2.02 and weblint, Red Hat EL 3

This should result in no warnings:

echo '<html><head><title>qwer</title></head><body><strong
id="asdf">asdf</strong></body></html>' | weblint -
- (1:45) Unknown attribute "id" for tag <strong>

but it gives:

    - (1:45) Unknown attribute "id" for tag <strong>

id is a core attribute in HTML4/XHTML1: http://www.w3.org/TR/html4/html40.txt