I think all of you guys are getting a little too serious about this thing. Here's my take: even in a 100% Microsoft shop, .pptx is a pain as much as .xlsx and .docx. And yes, I know about the free "fileformatconverters.exe", thank you very much. It does not work on my Microsoft cell phone that does not read .pptx, but does read .ppt. .pptx is a pain in the arse. I don't care if it's standard, legally standard, IETF approved, de-facto standard, or anything. Even if one is using a newer version of PowerPoint, one can "save as" .ppt. .pptx is just like HTML in a mailing list: just say no. Michel. _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf