Like the Elize'leerit and the Deep Hunters, the Icenaye operate on a caste-type system. The Icenaye make up the Ceph Faction. Most Icenaye suffer from a genetic defect that results in severe ADHD and twitchy reaction times. This makes them great in tactical operations, but as a whole they need to work in large groups in order to keep their attention focussed on something important, such as strategy. Constant reminders of what they are doing (or should be doing) also help.
The first and most important thing to remember is that none of the Castes are officially defined in any way, and most Icenaye that can fit into a Caste might actually be doing something else.
There are several Military Castes, and until the Ceph understand ACUs and ACU warfare, all Military Castes are soldiers or intelligence division.
Despite their menacing appearance, Stalkers make up 90% of the Ceph Military, although it is noted that a large amount of them can later be sorted into other Castes. All Stalkers are highly agile thanks to their highly manouverable armour, and are highly trained in hand-to-hand combat as well as firefight proficiency.
Elites are even more menacing in appearance, but they are simply a step above the Stalkers in fighting and/or leadership, not agression. Some of these may be in the Assassin Caste, although to keep their profile solid they remain classed as Elites so their cover isn't blown. Not that they have been needed yet.
The other Elite Caste is known as the Guardians. Guardians are the tactical operatives, equipped with the best armour the Icenaye can understand (and therefore safely operate), and are considered amongst the Stalkers as "The best of the best."Despite this, most Icenaye fail to grasp the concept of "Common Sense" such as don't grab certain things or people.