I say leave the "advertising" of airsoft up to each local club. Maybe us a general template of having some approved material that should be included on the advertising. This way each club can custom tailor the advertising to their individual club needs (milsim, run&gun, re-enactment, etc.). Not to mention that what might eventually be 'acceptable' or approved say in Calgary, may not be accepted in Ontario and so on. Each Province and even municipality, will differ on their views and outlook of airsoft.
I think the best thing we as airsofters can do is to properly and responsibly represent ourselves, airsoft and our local clubs when dealing with the public. Be somewhat pro-active if you can. I think most police and general public won't have a huge issue if they know that clubs use airsoft guns in a safe and controlled enviornment. None of this 'back yard counter-strike' BS goes on. In fact I'm sure it's a huge help to them that we do play airsoft in this manner. After a while, they (police) will know that if there is an incident with an airsoft gun in public, that it's a very good chance that you and your local club members have nothing to do with it.
The BCAC have a great rapport with the local police and RCMP in Vancouver to the point where they have contacted the club asking for assisitance in tracking down "offenders" of airsoft guns. This has even lead to discussions of having an "open house" where the local police and media would be invited out to view and partake in some skirmishing. So far this has just been in discussion within the club.