HTML 4 DTD の注釈 (参考) には
identifies an implementation
param を使うべきです。 HTML 4.01 13.3
 Java applet の例
<OBJECT codetype="application/java-archive" classid="java:program.start" codebase="http://foooo.bar.example/java/myimplementation/"> <!-- 代替文 --> </OBJECT>
(HTML 4 仕様書より、改)
 ActiveX control の例
<P><OBJECT classid="clsid:663C8FEF-1EF9-11CF-A3DB-080036F12502" data="http://www.acme.example/ole/clock.stm"> Clock: This application is not supported. </OBJECT>
(HTML 4 仕様書より、改)
<P><OBJECT classid="http://www.miamachina.it/analogclock.py"> </OBJECT>
<OBJECT id="myControl" classid="http:ControlLibrary1.dll#ControlLibrary1.myControl" VIEWASTEXT></OBJECT>
On Thu, 20 Nov 2008, Michael A. Puls II wrote: > > The spec currently says that Opera, Firefox and Safari can use the > classid attribute to load the plugin if they want. This might be done by > mapping a classid to a plugin handler. They just need to fall back if > that fails, instead of then trying type and data. > > The danger of mapping classid for non-activex browsers is that sometimes > an <object> that uses classid="" might be meant for an activeX plugin > that uses a different API than the NPAPI version of the plugin. This > where vendors would have to be careful before deciding what classids to > support. > > If that's not the handling intended by the spec and classid is meant to > be IE-only, the spec should be clarified. classid isn't a valid > attribute, so maybe that doesn't matter. What you describe is what I intended. There's a commented list of IDs that maybe they should support (based on what they do support) but I don't know whether to make it formal or not. So far I've opted to not make it formal. I think it might depend on a platform-by-platform basis.
clsid:6BF52A52-394A-11D3-B153-00C04F79FAA6 is for the WMP 7+ api. It uses a different API than the 6.4 API that's used by the NPAPI 6.4 wmp plugin (npdsplay.dll) that uses application/x-mplayer2.
So, mapping the classid in this case can break things, like volume, file loading, autostart etc and others things, including scripting.
However, clsid:22D6F312-B0F6-11D0-94AB-0080C74C7E95 is the 6.4 classid. It's still meant for the activeX 6.4 plugin, but it's pretty compatible with the NPAPI 6.4 wmp plugin.
Yeah... I think I'll leave this unspecified.