Maintainer of the W3C HTML checker (validator) here. The rel=apple-touch-icon-precomposed
error is because I recently updated the checker to conform to HTML spec requirements for sizes
:
The sizes
attribute is used with the icon
link type. The attribute must not be specified on link
elements that do not have a rel
attribute that specifies the icon
keyword or the apple-touch-icon
keyword.
About the error for role=banner
on nav
, that’s because the checker conforms to requirements in the ARIA in HTML spec that nav
must not have any role other than navigation
.
But note that the ARIA in HTML spec also states the following requirement:
Web developers should not set the ARIA role
and aria-*
attributes to values that match the implicit ARIA semantics defined in the table.
And requirements in “the table” cited state that the implicit semantics of nav
are navigation
.
Therefore, if you use role=navigation
with nav
, the checker will emit a warning.
So bottom line is, per the ARIA in HTML requirements, nav
should never have an explicit role
.