What, exactly is a compulsory trade?

Compulsory trades (TQAA classification)
are similar to restricted trades under the ACA (see Restricted trades, ACA) in that they are trades that may be practised only by certified Journey persons (Qualified Trades people) or registered apprentices.
In the case of students earning cooperative education credits as part of OYAP, they are exempt from this rule and are treated as if they were apprentices.
However, students working outside of the hours specified in their work education agreement must be registered apprentices