Matt,

Technical according to the TCDS. Also technical according to what a type rating would say if there was one. Citations are CE-500, CE-750, etc.

My actual logbooks don't differ between say, a 172M and a 172SP. My electronic one does for insurance, I had a couple owners who's insurance wanted to differentiate between TAA aircraft.

The PA-28 family is a fun one. For those I wrote the full designation. PA-28-161, PA-28-235, etc.