Different groups create the standards they require, Say some one trains as a paramedic , there exists patches to that skill already, so with that in mind, that level of skill receives a patch to the degree of their training in that area. I have basic first aid and CPR , my patch would only reflect that information. If I choose to advance that training and can prove it, then a more advanced patch is required. What benefit is it in a group like this ? In a post apocalyptic event, should any of us meet, there would be an immediate recognition of a kindred spirit and their skills . Even if ones patch only reflected the skills of duct tape and bailing wire, it still is the reflection of recognition others have invested. If however said person can't find here way out of a paper box,(so to speak) it might be accurate to assume that they lie about their skill. and not much they say is of any value . So even strangers might have a means of recognizing gold from iron pyrite .