Each cache can be assigned attributes by its owner. These assist finders by alerting them to what facilities are available near the cache, what times it is available, unusual hazards, the need for special equipment etc.
When setting a cache, select the appropriate attributes by clicking on them, and they will turn from grey to blue. Click them again to turn them off.
Both when setting a cache and when looking at a cache page, allowing the mouse pointer to hover over the attribute icon should display a brief description, which should be self-explanatory.