But in the real world its meaningless
Rather like logging instrument flight time in your log book. That column is probably faked more than any other log book entries. Apart from initial instrument rating course where progress reports should be kept and audited, there is no way that a pilot's claims that he has been flying in IMC whether on autopilot or hand flying, can be verified (audited). Worse still we see the ridiculous situation where pilots log instrument flight time at any time they are on an IFR flight plan and flying CAVOK the whole way.. Even taxi time is logged as instrument flight time purely because the aircraft is about to depart on an IFR plan.