Alerting is not optional and players need to know which bids in their system are alertable. The purpose of alerts is to tell your opposition that your partner’s bid is substantially different from what they would expect. (The opposition players may ask when it is their turn to bid. They do not have to ask for an explanation immediately, but may do so then or wait until later.) Do not alert bids that are basically what you would expect from “natural” bidders.
The Club has an alert procedure, which is posted on the notice board and is repeated here. The principles shall apply in club grade play. (The NZ Bridge alerting regulations for tournament play, are at: http://www.nzbridge.co.nz/directing and see Policies, Rules & Regulations page D43).
At the Christchurch Bridge Club, Acol is the standard system that most people play. If you play a standard version of Acol, you will not need to alert anything. If you play Precision, Standard American or any other system, or if you have modified your Acol, the onus is on you to make sure your opponents are aware of what you are doing by alerting (circling partners bid on the pad) and giving clear explanations when your opponents ask.
Before the auction:
Tell your opponents if your system is not Acol, or if you have modified Acol (eg multi 2D)