Carol, that what you wrote about enforcing the rules sounds really needed, but its really not. The key to this is - common sence!
Upon implementing common sence into reffereeing, a lot of rules can be implemented without trouble. I cant help not to point a finger at US refferees when it comes to nit-picking the rule book. There are several cases, one of them is that Mareh is now making gloves specially and only for US market, as your refferees seems to be without common sence when it comes to glove colour. Black is good, red is not....??? And whats that story about US players needing to wear t-shirts in the game without a serius sponsor demanding it becouse of a commercial or outside reasons??? Whatta drag! I hope that none of US refs will come up with rules about fin-colour..... (

decided not to comment further...)
Regarding the direct text of the rules about subbing, one can easilly write and enforce the rules correctly, while allowing what Tuck has proposed. Again - common sence beats problems of unforceabillity. Example: How can anyone prove that you drove your car without a seatbelt? And most of us had to pay it at least once in a lifetime. Thats the authority of policeman. The similar authority is carried by refferees... end of story!
It looks to me, that some refferees think that players are in the pool becouse of them, not the other way arround. Again, thats the problem of common sence!