Providing rules will help ensure that people are educated about using the community compost site and will help to minimize the cleanup burden on volunteers or gardeners. You can either purchase a rules sign for (AmeriSigns is creating a template for this) or make them yourselves with this verbiage. Some great sign material includes paint, primed plywood, old sandwich boards, or whatever else you think would be appropriate.
As important as good signage is, you will still need to ensure that the compost site does not become merely a dumping ground. If the proper proportions of brown to green material are not maintained, odors may become an issue and the composting process will be hindered if not halted. If contributors are stashing fish and meat scraps or the contents of cat litter boxes, unwelcome rodents and pathogens will invade your soil machine and make a mess of the composting experience for everyone. Lastly, improper sorting or careless mingling of plastics or other trash in the compost can become a problem. Nobody begrudges a produce sticker or occasional rubber band in the finished compost, but if trash becomes excessive, your compost product will suffer and gardeners may not be sold on using it.
Many community gardens have rules committees that cite plots for minor infractions such as copious weeds or unkempt, rotting produce. Engage the rules committee to inspect the compost site from time to time to make sure the brown source is being used adequately and the site is not becoming trashy or unsightly. Of course, the nature of a community compost site – unlike a private plot on shared property – is that access to it is public and often anonymous; there may be no way to track improper use to a particular user. The important thing is to have people watching out for the compost, taking collective responsibility for it, and embracing it as a valuable resource for the garden community and real estate.