What is a non-immigrant O-B visa?

Someone tells me you can work with such a visa in certain fields (sourcing, purchasing etc) without any work permit ... seems odd!

No such Visa that I know of.

There is no such visa.

See: http://www.mfa.go.th/main/en/services/123/15398-Issuance-of-Visa.html

Most likely they were referring to IB visa. Since it's related to BoI, the work permit regulations can be a little different.

Thanks for the confirmation.