I have read several times on Thai forum, people using the name "Somchai" as a sort of equivalent to the English language usage of "John Doe"

is that correct? I know it is a popular Thai name

I've met many Somchai's during my staying in Thailand, but never met a John Doe in Europe or America.

Somchai is a common name here like Costas in Greece.

So Somchai is a real person while John Doe is an unknown person.

yes

no somchai is john smith or joe bloggs, john doe is an unidentified male corpse

No, it is more akin to Mr. Smith,a common name, no semblance to John Doe which is a term for an unidentified individual..

Excuse me. I meant more along the lines of "John Smith", as it was pointed out "John Doe" is for the unidentified man.

We use the name Somchai for the guy who can fix everything and anything. He has an old hammer (that he forgot to bring) and if he doesn't show up then his motorbike had a problem. He gives a great service and always comes back a few times to adjust/repair some things, mai ben rai krab sabaai sabaai.

no somchai is john smith or joe bloggs, john doe is an unidentified male corpse

Which doesn't sit well, with the real John Doe.

Of course you are correct and I believe it's female equiv is Jane Doe.

Somchai is normally banging your smoking hot young TG, although you think he's her brother

It's a euphemism for whatever "your" particular angle on the "typical" Thai male is.

So it can be used favourably or derogaritively depending on the context used. In NZ or Oz we might say either "some prick", or "good bastard" meaning your typical bloke that did something either very bad or bery good.

Yeah, it means "John Smith" but whoever actually uses that phrase in real life.....except a genuine John Smith?

joe blow

No, this is my real name.

You are a "manly man."

Or in the case of, say, Somchai the champion boxing chicken, he is a winner.