I was "FIM'd" on a US flight a few months ago due to misconnect. I was on a DTW-GSP "direct" flight, which meant it stopped in PHL. We were delayed departing DTW due to weather, so we missed the connection to the 2nd half of our "direct" flight. The computer showed my ticket as being used, as it could not distinguish how we were stuck in PHL since we were "direct" to GSP. So, a FIM was issued, which appears to be like a paper ticket essentially. The CSR filled it out by hand, and stapled it to the boarding pass. It looked like it could also be used for an interline as well.