Following consultation, the GAGB committee have reviewed the comments and suggestions, and have decided to modify the "Urban" guideline as shown below. One of these changes is to move away from defining "Urban" to focussing on overlooked locations and where finders could be considered suspicious.

We are working with ACPO to provide the Police with a process for reviewing suspicious packages which will include online access, mapping tools and ideally cache reference numbers to speed this process.

New guideline follows:

Caches should be hidden so as to minimise the chance of security alerts, particularly where there is a liklihood of finders being considered suspicious for example where a cache is overlooked by houses / offices / shops / people.
When a cache is placed in an overlooked location, the cache owner should help finders avoid being considered suspicious by offering a clear and unambiguous hint on how to retrieve the cache quickly.
Cache owners should mark caches externally with the relevant listing site reference (eg GCxxxxxx, OXxxxxxx, or OCxxxxx) wherever the cache is big enough for this to be written externally. This will offer the Police a better way to identify a suspect package as a geocache.