What do professional pilots keep track of in their pilot log books? Professional pilot logbooks (either paper or electronic) always seem to be more elaborate than those used by private pilots.  

I am curious as to what a professional pilot finds important to track in their logbooks besides just total flight time in aircraft type.
The experience required is simply flying hours on the type or configuration, and flying hours, for pilot logging purposes, is time from engine start to engine shutdown.  If you're flying an airplane with a Hobbs, which usually starts/stops using oil pressure, you can just use the Hobbs value.  If no Hobbs, record the engine start/stop time yourself and use that, or if you forgot to, just use the tachometer hours reading (which is closer to air time, or time airborne) and add a 10th.