using "variables" (correct term?)

[Steven Arntson]

Perhaps what I'm really searching for here is just the correct term,
because I don't think it's "variables."

I'm trying to send out some form letters to various people, and am
looking for a way to define something at the top, like:

     #+RECIPIENT: Jane Doe

which would automatically replace itself in the letter when referenced
with "RECIPIENT". Is this called a "variable"? How would I go about
doing it? I'm using org-mode, but the solution needn't be org-based.

Ever-a-newbie,
Steven Arntson