Sierra (Callsign)

**Sierra** is the nineteenth letter of the NATO Phonetic Alphabet, corresponding to the letter "S". The word Sierra is normally used instead of that letter in all communications.

The term "Sierra" is almost invariably used as the callsign for support Vehicles, primarily ones operating as a Vehicle Section or Vehicle Platoon. This callsign is distinct from "Mike" primarily in the types of vehicles used, and the way in which they cooperate with the Infantry. For the most part, "Sierra" vehicles are lighter, faster, and/or capable of ferrying troops on the battlefield. This callsign seems to apply to both BLUFOR and OPFOR vehicles.

## Uses

In ShackTac military parlance, the letter "S" is short for "Support". Thus, the callsign "Sierra" is assigned to vehicles whose primary purpose is to provide close support to the Infantry. Typically this involves light fire-support and transportation. The vehicles receiving this callsign will accordingly be armed Jeeps and APCs.

"Sierras" are generally incapable of defending themselves effectively without the Infantry's help. Consequently, they stick close to the infantry whenever possible, providing a strong base of fire against enemy infantry as well as some protection from enemy vehicles.

Many "Sierras" are capable of transporting infantry as well, and may be required to do so several times during the mission. This is not true for every type of "Sierra" vehicle, but the ones that can transport infantry will be able to carry roughly one Fireteam, and may need to do so during the Insertion and/or Extraction phases at the very least.

Sierras rarely move away from infantry, but can expect to be moved to whichever unit needs their assistance at any given time. The crew of a Sierra may even switch their radio to the frequency of a nearby infantry Squad to maintain better coordination. If each "Support"-class vehicle is intended to operate closely with one particular infantry Squad, they may instead receive a callsign based on the name of that unit, e.g. "Bravo Vehicle" ("Bravo Victor") for a vehicle intended to support Bravo squad.

If the vehicles are heavy and powerful enough to hold their own, and are not expected to support a specific infantry unit, they will typically receive the callsign "Mike" instead of "Sierra".

Multiple vehicles in the same mission may receive the "Sierra" callsign, in which case each vehicle's callsign will be succeeded by a number, e.g. "Sierra 1" (or "S-1"), "Sierra 2" ("S-2"), and so on. There are typically no more than 4 "Sierras" in any given mission. If one vehicle is designated as the leader (coordinating the movement and actions of the other vehicles), it may be referred to as "Sierra Lead". When referring to a specific vehicle without knowing its exact number, one may simply call it "The Sierra"; This is commonly done by infantry to refer to a vehicle that is directly nearby. Similarly, all "Sierra" vehicles can be referred to collectively as "The Sierras".

Objectives for a Sierra vehicle are marked with the letter "S" (followed by the vehicle's number, if it has one). They will still be referred to as "Sierra-1 Objective", "Sierra-3 Rally", "Sierra Resupply", etc.

The term "Sierra" is never used as a callsign for any other kind of unit.

### Exceptions

Vehicles conforming to the role outlined above are not always given the callsign "Sierra". There are several other possible callsigns for such vehicles, in specific situations:

* OPFOR vehicles tend to receive Soviet-themed callsigns, including "Hammer", "Sickle", "Bear", and others. Nevertheless, OPFOR missions have included the "Sierra" callsign for such vehicles in the past.

* When a support vehicle (or a group of such vehicles) is tasked with assisting a specific infantry Squad, it may receive a callsign based on that Squad instead of "Sierra". For example, a vehicle tasked with closely assisting Bravo squad may receive the callsign "Bravo Vehicle" (or "Bravo Victor") to indicate this. In such cases, the vehicle may even be under the direct control of the Squad Leader, rather than the Platoon Leader/Company Commander.

* When there are two or more distinct groups of support vehicles in the mission, the term "Sierra" may be dropped altogether, with each group receiving a different callsign (typically following the Alpha Victor / Bravo Victor / Charlie Victor / etc. template). Such cases are relatively rare in ShackTac missions.

* Sometimes (and particularly in older videos), even heavier vehicles may receive the callsign "Sierra" instead of "Mike". Normally, this callsign is used for vehicles whose main purpose is to transport infantry and protect them, working in closer coordination with the infantry than "Mikes" typically do. This practice has slowly been phased out, giving the term "Mike" a clearer distinction as referring to heavier support vehicles.

## Examples

The term "Sierra" is exceptionally common in ShackTac videos, and is featured in a very large number of mission videos. Specific examples of its typical use are therefore not required.

Nevertheless, please add below any examples of the term "Sierra" being used in an unusual or unconventional manner (for example, when used for infantry units, heavier vehicles, tanks, etc.).

* *Stop Loss* by **Dslyecxi**: The callsign "Sierra" is given to four supply trucks that are being escorted by the platoon. None of these four vehicles are armed.