In grammar rules, an antecedent can be identified in a sentence because it is later replaced by a pronoun. An antecedent also refers in a sentence to something that happened in the past.
In the sentence provided as an example, the Venetian 'merchants' is the noun that is later replaced by its respective pronoun (theirs). The verb brought also tells us it was something that happened in the past.
I believe that peer is referring to someone else who goes over your paper or report and then puts checks next to things you need to work on or that you have done.
