If a Trust Can't be Party to Contract, How Are Owners Confirmed?

[Josef Roberge]

"A Trust name is not party to a contract, it is not a legal person as a corporation is. The Trustee is the proper signatory. "

Well this properties deed is under "Spratling Living Trust". There are three co-owners with 3 different last names. 

So how does escrow/title company know that these 3 are the three owners of this trust? How is ownership confirmed? 

Should the trust name be anywhere on the Purchase contract?