Just one question
Does anyone know where T-DOC gets their data from?
As I mention above IATA uses the same data as that used for the TIM/TIMatic (IATA is now the publisher of these as well). Meaning that a punter should get the same answer as the check-in agent behind the counter.
I'm guessing that IATA's (or TIM's) data source is their 250-odd member airlines.