Meaning of "currency in this field of disclosure"

This use of currency is not the first definition listed in any dictionary but is still an accurate use of the term. It is in no way bending the use nor taking liberties with the true meaning. It means a medium or means of exchange.

Originally gold and silver were traded for goods and services. They were (largely) immutable and could be easily tested for their purity. Dollars used to be promises to give over gold for the paper before Roosevelt found a reason to stop it. The paper currency is what we use to trade for items of value. The use of the word away from paper money seems confused when it is actually exactly what paper money is and is used for.

The meaning here describes the terms "employer", "employee", "principal", "independent contractor" as the parts of regular language of the law. Describing the area as "this field of disclosure" indicates practical and purposeful boundaries to the use of these terms. They are the means by which meaning is conveyed in this subject; they are the medium of exchange.