[whatwg] Hyperlinks with |title| attribute

Should (or may) user agents display the content of the |title|  
attribute of an |a| element in the GUI window caption (if the window  
manager used supports such), when the user followed the link and the  
retrieved resource is in a format that does not support specifying a  
title by itself (e.g. many image formats)?

What about resources that could have a title but do not (e.g. a non- 
conformant HTML document without |title| element)?

The alternatives are to display nothing or the name of the resource  
("file name"), the final part of the path.