There are airlines that want your PIC time to be "acting PIC" time, not just FAA-loggable PIC time. I'm sure not going to not log time that the FAA says I can, but I did recently decide that in case I ever go to a place that wants that, I should be prepared.
Thus, I added a custom field to my ForeFlight logbook for "Acting PIC" and went back and filled it in so that I can answer that question.
I also have one I called "seat time" which I use for any time, loggable or not. That's a result of having spent several hundred hours in a single pilot turbine aircraft in a multi crew environment, where a good amount of experience isn't loggable under FAA rules. Thus, I can say "I have 550 loggable hours in a crew environment, but 1100 hours of actual time spent in the aircraft." I don't put this on the resume at all, but it's something that I can talk about in interviews.