Reading all these different responses to whether or not a First Officer, typed rated or not, can ever log PIC time in a 121 operation begs me to wonder what everyone logbook looks like! I'm sure most of you all were flight instructors at one time and taught FAR's. The person, the non-airline pilot, who asked the original question is probably scared out of their wits reading about how there’s no clear consensus among actual airline pilot about whether or not they can log "pilot or co-pilot" time.