As mentioned offtopic in <http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2006-November/007936.html>, just like OBJECT, for EMBED, the src attribute is not always needed and sometimes it must not be present.
The best example for not requiring src is the tcl plug-in. <http://shadow2531.com/opera/testcases/plugins/tcl/001.html> <http://shadow2531.com/opera/testcases/plugins/tcl/001-a.html> Also, Java can be loaded via the embed element where src is not needed. <http://shadow2531.com/opera/testcases/plugins/java/007.html> There are other cases with the Windows Media plug-in or with the RealPlayer plug-in where just loading the plug-in with the type attribute and doing scripting on the object is desirable. There's also the neptune plug-in. For example: <embed type="application/x-meadco-neptune-ax" param-location="your-entry-page.htm">. In this case, it wants a param-location param and not a src param. -- burnout426
