It is actually very difficult for me to write instructions that detailed
(and I'm far from the best of the MVPs in this regard). The part that I
debated about was the actual creation of the signature line. Constructing an
IF field is very simple (and I'm sure you already knew how to do that). What
many users don't appreciate is that the "TrueText" and "FalseText" can be
just about anything. But if you try to create the text directly in the
field, it can be confusing (especially if it includes line or paragraph
breaks), which is why I suggested creating it separately and then pasting it
in.
You could equally well use an AutoText field as the TrueText (when you use a
field, you don't have to use quotes around it). And of course you could
create the signature line in the document itself and cut or copy it from
there, but that would require stepping out of the footer pane and back in,
which would be more complicated for some users. The danger in creating it in
the footer pane is that sometimes when you cut text from a header/footer
(even if you include the paragraph mark), an empty paragraph is left. I
didn't test this, so I can't say whether that would happen in this instance
or not.