[Commentor] LC-1978 Dominique Hazael-Massieux (archived comment) [Comment] * when analyzing external resources (in ContentFormatSupport, PageSizeLimit, ExternalResources), the objects and images that are set as fallback of an object that is in an acceptable format shouldn't be counted. For instance, shouldn't trigger an error in ContentFormatSupport, the weight of myimage.png shouldn't be counted in PageSizeLimit and ExternalResources [Commentor reply] yes [Working Group decision] 
We agree that the "myimage.png" should not trigger a CONTENT_FORMAT_SUPPORT error, and should not be taken into account in PAGE_SIZE_LIMIT and EXTERNAL_RESOURCES. This is triggered by the note in 2.4.6 Included Resources: "object elements that are accessed in order to test their Content-Type HTTP header, but do not form part of the ultimate representation of the resource under test (see 3.15 OBJECTS_OR_SCRIPT ), are not considered to be included resources". We agree that the notion of "ultimate representation of the resource" deserves to be clarified though and the note extended to resources retrieved by section 3.15.1 Object Element Processing Rule. On the light of the discussion that followed your other comment (LC-1980) on the use of the HTTP Content-Type value to taste object element, we updated the note to specify that only resources retrieved under the 3.15.1 Object Element Processing Rule whose Content-Type is image/gif or image/jpeg are considered to be Included Resources: http://www.w3.org/2005/MWI/BPWG/Group/Drafts/mobileOK-Basic-1.0-Tests/080707r#included_resources