As a "uniformed civil service," the Sheriff's Auxiliary uses a rank structure and courtesies based closely on common military organization. The advantages of a military structure are clear lines of authority and chain of command in emergency situations, but they may not be familiary to people without a military background. This article and associated talk will provide a brief background on how the rank structure works and proper etiquette toward volunteers, law enforcement, and other personnel in military-structured organizations (such as the National Guard or the uniformed members of Health and Human Services). In particular, we go over the difference between officers and enlisted, identifying rank insignia, how (and when) to salute, and other formalities that come with a uniform.
[Version 1.0 Partial Draft]
Officers and Enlisted Defined
One of the first things one should understand is that a military organization normally has two separate rank hierarchies, one for officers and one for enlisted (non-commissioned officers are "enlisted"). The Sheriff's Auxiliary is no different in this respect. This may make things seem complicated, but the difference is actually fairly straightforward: "officers" are members who officially hold an "office" and are a representative of the elected OFFICial who commissioned them (the county Sheriff in our case). A commission is a formal legal document making someone an officer. Officers have a legal responsibility to their superior and to the public to carry out the duties of their office. As the leadership of a unit, an officer determines WHAT must be done, "What is the mission?" and, particularly, what may NOT be done because it is beyond the authority of their office. Officers in the Auxiliary are therefore effectively county officials of minor rank (a "public safety officer").
The word "enlist" means "to call-up or to request help from someone". If you have been enlisted, you have been "called-up" to assist officers in carrying out their duties. While an officer decides what must be done, enlisted help them actually do it. Someone who is enlisted has no legal authority in their own right, outside of whatever mission has been assigned by an officer. Someone may volunteer to enlist and become part of the organization, or they may be enlisted temporarily when needed during an emergency. In dire emergencies, enlistment may not be voluntary: the county Sheriff, for instance, has statutory authority to enlist citizens for the defence of the community as part of a posse or to recover escaped criminals.
Non-Commissioned Officers
So what is a "non-commissioned officer"? A non-commissioned officer, abbreviated NCO or "non-com", is an enlisted volunteer (because they do not have a commission) who has valuable skills or experience and are given authority over other enlisted volunteers. While commissioned officers decide what must be done, and enlisted make it happen, non-commisioned officers decide how something must be done based on their skills and experience. An NCO's expertise may be in tactics, in first aid, communications, financial matters, or virtually any skill an organization needs to function. Typically, the officer corps of a unit or organization builds up leadership skills while the non-commissioned officer corps builds up technical skills. As enlisted personnel are often transient or may even be called up for a single event, NCOs bring new recruits up to speed, solve problems, set the pace, make sure that tasks are carried out properly, and report to their assigned officers.
Ranks and Insignia in the Auxiliary
Ranks in the different branches of the military (e.g. Air Force vs. Navy) are somewhat different and can be confusing. The ranks used by the Auxiliary follow a simplified version of the US Army ranks and are listed in the Organization Document, showing their respective order. You can see all of the ranks and insignia used by the various branches on the DOD web site. It is useful to learn some of them so that you can recognize insignia of different organizations, but focus on what we do until you are comfortable. Navy/Marine ranks, in particular, can be quite complex.
The commissioned ranks, from bottom to top are Lieutenant (Junior and Senior Grade), whose insignia is a single bar or either brass (Junior) or silver/black (Senior), Captain with an insignia of two black/silver bars, and Major, with a brass oak leaf. Most military organizations also have Lieutenant Colonel, whose insignia is a silver/black leaf, Colonels, with a silver eagle, and Generals, with one or more stars for insignia. We treat all deputies as if they were Lieutenant Colonels and the Sheriff as if he were a Colonel. In fact, Sheriff's traditionally hold a rank equivalent to a Colonel, which is why many Sheriff's, including ours, wear a silver eagle on their formal uniform. An officer's rank insignia is usually worn on the shoulder tabs ("epaulettes") of their uniform or on their collar if their shirt does not have epaulettes. Epaulettes look like handles and, originally, that is exactly what they were: they were used to drag wounded soldiers clear. Many modern militaries have a single handle on the backs of tactical vests for this same reason. 
Officer Insignia is defined in the Volunteer Handbook (with links to pictures).
The bottom-most enlisted rank is the Private, whose insignia is a single chevron (an inverted V). Traditionally, the chevron was sewn onto the unform sleeve in black or gold piping. Most modern organizations use shoulder/collar pins in the same way as officers.
The Non-Commissioned Officers start with Corporal (two chevrons). The Army also has the Specialist rank (a chevron with an arc underneath) of equivalent authority. A Corporal or Specialist is a Private with some additional skills and expertise. Next up is the Sergeant, which is considered a significant non-commissioned rank. The insignia of a Sergeant is three chevrons (see the pattern?) Sergeants are the backbone of military organization and are often squad leaders. A Master Sergeant's insignia is three chevrons and three arcs. A Master Sergeant in most organizations has substantial training and experience. The highest non-com rank in the Auxiliary is a Sergeant-Major, and the insignia is the same as a Master Sergeant with a star in the center. The NCO insignia is defined in the Volunteer Handbook (with links to pictures).
Lastly, we have the Warrant Officers. Warrant officers are the highest enlisted rank and the lowest officer rank. A Warrant officer is an enlisted who is usually an expert in a particular field or skill (e.g. medical, computer security, engineering, tracking) and who acts as an officer when in charge of missions related to their field. So, basically, if you have a warrant officer who is an expert in engineering and demolitions, they would have the authority of a commissioned officer when supervising the clearing of a roadway, but only the authority of a non-commissioned officer when directing traffic or in a patrol. This is a purely legal distinction, but an important one. Warrant officers can also be used as a bridge to transition a senior non-commissioned officer into a commissioned officer, sometimes referred to as a "mustang". A warrant officer's insignia consists of a line of one, two, or four black squares (we skip some warrant officer ranks available in other services).
Military Formality
At its core, the purpose of military formality and cermony is to clearly define who is in charge. Some branches of service are more formal than others (the US Air Force being the most informal), but some level of formality is a necessity to establish legal responsibility and to ensure clear communication when lives may be at stake. In military formality, a subordinate almost always repeats back some portion of an order to convey that they understand their assignment (especially true in the Navy): "I am ordered to hold this postition until reenforcements arrive. Yes, Sir." This is no different from proper radio discipline: "I copy 3 injured needing evacuation." Formality must be observed and acknowledged whenever authority changes, such as at the start of a new shift. This leads to the common formula: "I relieve you, Sir," "I stand relieved," to make it clear to everyone nearby exactly who is in charge. In the Sheriff's Auxiliary, we tend to be informal off the field, but unless formality is practiced, it will not be familiar when it is needed. The Volunteer Handbook contains a discussion of courtesy and formality.
Courtesy is related to formality ("courtesy" equals "courtliness"). Courtesy is recognition of service, of rank, and authority. It is also simply showing of respect. Military courtesies often slow down the action in order to ensure that the required formalities occur. Saluting is a show of respect to an officer, but by teaching soldiers to salute, it also ensures that new recruits learn to recognize rank and insignia and to demonstrate that knowledge before being placed in a life-or-death situation. Saluting and other courtesies also serve security by encouraging one to actually look at and acknowledge a new arrival. This provides an opportunity to recognize that something is not right or that someone does not belong. Meaningless formality or rigid adherence to rules of courtesy serves no purpose. Using rules of formality to belittle or harrangue is what many soldiers refer to as "chickenshit" and is the opposite of courtesy. Finding the balance is not easy and often depends on the style of an individual organization and commander, but if one starts from the principles of respect and making clear lines of authority, it becomes easier. Typically, the NCOs of an organization become the repository of tradition and provide the example for new recruits. As a new organization, establishing that tradition in the Sheriff's Auxiliary will require time and effort.
Volunteers, especially officers, are expected to demonstrate appropriate courtesy at all times and places, in and out of uniform, on and off the field.
Saluting
Saluting is a topic which often worries new recruits afraid of getting it wrong. Again, because the Auxiliary is a new organization, thinks are more complicated than usual. If you start out at the bottom as a private or a cadet and work your way up, who to salute is obvious: "If it moves, salute it. If it doesn't move, polish it," or some variation is common in military academies. By the time you get your first promotion, the rules are old hat. We, however, have volunteers starting out in leadership positions because those positions were empty and needed to be filled. The Volunteer Handbook has a section on saluting, from the basics to the more obscure situations and including some history of where it came from in the first place. We summarize here. In general, we follow the rules for uniformed civil service.
First of all, only officers are saluted. An enlisted volunteer salutes all officers. An officer salutes all officers of higher rank. An officer receiving a salute returns it. An enlisted volunteer does not salute another enlisted (e.g. a Private does not salute a Sergeant). We only salute when in uniform, outdoors, and covered (wearing a hat). We salute officers of other uniformed services (e.g. National Guard; if in doubt, and they have formal insignia, salute an officer). Other services may or may not return our salute, but we don't concern ourself with that. We also salute our Deputies and the Sheriff as our legal superiors. They are not required to return the salute. In much the same way, the military salutes the President as their Commander-In-Chief, but, unless the President has also been in the military, the President does not normally return the salute.
A color guard (someone carrying the flag in a ceremony) is always considered an officer and always of superior rank. In this case, you are saluting the flag, not the bearer. There are also special rules for funerals and for personnel on guard duty ("service under arms"). During the ceremony of raising or lowering the flag (usually morning and night) or during the National Anthem, we also come to attention and salute for the entire duration.
Conclusion
Hopefully this article and the linked sections of the Organization Document and the Volunteer Handbook will give you a start on understanding the role of military courtesy in the Sheriff's Auxiliary. This article was written to organize notes for a short talk which will be given at the meeting this evening and which will be repeated from time to time. If at any point you are confused, don't be afraid to ask questions. If you see someone with insignia you don't recognize, politely ask them: "I'm sorry, I'm not familiar with Navy insignia. What is your rank?"