How long do they last?

In the Leeds v Catalans game the ref warned the team. A while later a penalty was given with no Yellow issued. Some time later he warned them again!!

I realise there was a red in there somewhere.

How long do they last? Do they end at some point or stand for the rest of the game!!

Why not just put a set time limit on it so everybody knows what the situation is?

The problem with a time limit is it almost comes across as granting permission to concede a penalty because it's the most favourable option for your team in that moment.

The problem with no time limit is you can get extended periods of good behaviour and then lose a player for some relatively obscure technical offence.

I like the principle of team warnings but I suspect we've already seen more in the opening rounds than we'll see for the rest of the season put together.

I thought that once Bailey was sent off the warning was over?

Clearly not, he could be heard to say the warning is still in place AFTER he sent him off.

And if someone gets binned because the team are in a warning, if they give away another penalty is it another sin bin?

I don't get what was wrong with the old system of just having a word with the captain and saying "sort it out or the next one's off". Nothing has actually changed with the "team warning" signal, other than the fans now being able to tell when a referee can't remember what he said five minutes ago.

Late in the game, Catalans conceded something like five penalties in ten minutes, yet no team warning was given. Not sure why.

There was about 15 minutes between the "team warning" being given and the next (non sending-off) penalty being given at the ptb against Joel Moon. Statler & Waldorf got quite exercised about this, but the warnings can't last for ever.

IMO it's daft to have a prescriptive rule about this and encourages the falling and faking and conning at the play-the-ball that Catalans seem to specialise in.

Terrible rule change that puts refs under pressure to sin bin for the most innocuous reasons. The hull kr sin bin for an alleged high tackle was a joke.

The League Express April Fool gag about this was well observed.

I have some sympathy with craigizzard and JB's views above.
Just leave it to the referee's discretion when an 'accumulation' sin-binning needs to be dished out. That way he can take into account the context and nature of the offence. The ref should only make his signal AFTER the sin-binning to indicate to the crowd it's because of persistent offending.
This business of telling the teams (effectively) 'Best stop offending for a bit' or 'It's okay to go back to offending now' is nonsense. If you commit offences, you're in danger of getting sin-binned. I don't see the need for prior warnings.

It is a good idea in theory but it needs doing properly - like a team sin bin that lasts for 10 minutes, next penalty goes then its reset and used again if the offending team carries on.