Thanks to all for the help. I have sold covered calls in the past but that was many years ago.
My intent today would be to bring in extra income from the call proceeds, but only if a stock made a significant move up and I felt that a decline was likely.
I hold a number of stocks that I would prefer to keep, so I realize that this is a risky proposition. My strategy would require good market timing and we all know how difficult that is.
I am located in the U.S. and apparently can be exercised before expiration as several of you have mentioned.