Personal style I guess, but please don't break in the middle of a tag?  Preferably do semantic linebreaking, where you break lines between signficant phrases.  It tends to keep your lines at 80-100 chars anyway.  At minimum, though, just push the start of the tag down to the next line.

Also, "attribute" is a WebIDL definition type.  You want "element-attr". Preferably specify the element as well, as `<a element-attr for=iframe>width</a>`.  (You'll have to silence the error in the "Ignored Terms" metadata, because these things are not adequately marked up in HTML for Bikeshed to link to them, but writing them correctly now will auto-upgrade them when the targets *are* marked up correctly.)