Source property, SHTML, and SSI

I just want to recheck how Server Side Includes work so that we are doing
them is similar ways...

Traditionally, one PUT's a *.shtml file at a specified URL and GET requests
to that URL result in the out put of executing the SSI.

I'd then guess that if one does a PROPFIND against that URL, one would find
a SOURCE property that points to someplace like
/ssifiles/n9876.shtml.

I presume that the server just generates that URI via some set of RULES.
Right?

If I do a GET on /ssifiles/n9876.shtml, I'll get the unprocessed source.
Of course.

I've already said that I should be able to do a PUT against the original
URL.  Should I be able to do a PUT against the generated url
/ssifiles/n9876.shml?

Does anyone envision SSI's typically working differently than this?

Thanks,

J.