Wikimedia Bugzilla is closed!

The sanitizer currently forces all pages to pass HTML validation individually.  This causes it to erroneously escape HTML which, when transcluded, would culminate in a valid page.

For example, if {{ROW}} contains:
<tr><td>Stuff</td></tr>

And is transcluded as:
<table>{{ROW}}</table>

The transcluded HTML will be escaped, instead of passed through.

Ideal solution:  Introduce a mechanism by which the sanitizer can be aware of the context in which it is intended to be transcluded, and validate it as though it were in that context.

Easier workaround:  When sanitizing a page in the Template: namespace, only check for well-formedness, rather than validity.