carpet set

[Gary Nafziger <naffy@netins.net>]

Bought a carpet set and am wondering how the sill pieces go on.  The long
strip of carpet for the inside sill area has a short section of vinyl sewed
to it.  It is supposed to go along the door area I think.  I cannot figure
out why it is there.  Does the vinyl part go inside under the floor carpet,
or outside and fits over the sharp edge with fuzzy door seal clamped over
it??  Can anyone help?
                Gary, Frances Nafziger
                Wellman, Iowa