Incorrect attributes in tags

Several times I have come across attributes that validate in Amaya, but
not w3c validator. The latest is an alt inside an <a> tag.
 An example is <a title="test" alt="another test"></a>
The incorrect alt tag validates in Amaya.

I wonder if it is possible to design Amaya to automatically know which
attributes are acceptable (and by inference what are not) in some sort
of general file, before it begins other more specific validation checks.

This is important to me because although I realise that Amaya does a lot
more than validate, I primarily use it as an editor / validator at which
it is generally so very good.

Cheers