This is correct. I had 2 (maybe 3) F codes last year. Each time was because I dropped a RES day via PB day or PD, leaving 1 day stranded followed by X days where I couldn't be forced to start before 10/noon. Each time, the afternoon prior, I got called for a multi-day GS reporting early the next morning. While I didn't get a PB day for that first day, I got the full trip value on top of RES guarantee. And each time scheduling coded it incorrectly as G#X but a quick call to scheduling and it was coded to F#X immediately.