In the U12-14 DA games I've seen in person or video some coaches and officials are still getting used to application of the sub rules and the detail accounting in the game reports.
For U13+ I've seen both coaches and officials argue about when subs are allowed, how many at a time, and how many total. The substitution pass card has all the info but getting every body to understand and use them properly is a small learning curve. The halftime subing is one area that has caused some confusion since it doesn't count as one of the 3 "moments". Why halftime is not a moment (tiny print on the card) is strange to some and that takes some getting used used to the terminology. A injury is a moment for example and counts as one of the 3 but I've seen them not count those and teams getting 3 other moments plus the half time sub. There is also a special suspected head injury sub rule that allows a temp sub for evals purposes but some don't know about that one much either.
The post game completion of the game day report/stats by the ref crew for the goals, subs, and misconducts that is verified by both clubs before they sign is suppose to catch any discrepancies. The number of misconducts on the reports vs actual in the game seems to be the one of the other area of concern during these reviews.[/QUOTEThat is why referees must read the handbook and pass a mandatory quiz before they can be assigned to any game.