Manually tested !
This one can generate a lot of issues on most real life HTML source files.
I actually plan to test all rules on our IT ruling to see which are the ones which generate too many issues.
At least it's not enabled by default.
There are false positives on:
<a href="c.html"><img src="a.png"></a>
<a href="d.html"><img src="b.png"></a>
Starting at 6,189 issues.
Down to 5,953.
I don't see false positives anymore, LGTM