I recently had a new exterior door installed and after it was installed
i noticed stickers on the vinyl clad mull posts that said "no caulk".
these stickers were right above the sill.  I asked the man who
installed the door what they meant and he said "don't put caulk around
the mull posts.  I am confused because this really looks like a place
where one should put caulking so as not to get a leak under the sill.
Has anyone ever heard of this?  The mull posts have a thin vinyl
covering over wood.  The jams have the same covering and they were not
caulked either.