Answer: Please accept my apology - In reviewing old theory questions I noticed this one that was received last year and never got a reply!

You may be thinking (if you're still thinking) of a "Picardy third." That's a practice going back as far as the 15th century, in which a piece in a minor mode ends with tonic chord whose third has been raised to make it major. In early polyphony the third was not admitted as proper for inclusion in a final harmony, but when it did come to be accepted the stronger consonance of the major third was preferred. While mood was probably not the original intention, this does give a somewhat optimistic cast to the ending of a piece.

As for the connection with Picardy or Picardie, a region in northern France, according to Willi Apel "no plausible explanation has been found" for the use of the term "Picardy," but I admire the explanation advanced by Robert Hall, that it derives from "picart," which can mean "sharp." To sharp a note is of course to raise it.