Hats

I've got the most hats, therefore I am the most commissar.

In the grim darkness of the far future, the size of your hat determines how important you are. If your hat appears to be larger than those around you, you may be an important person!
You do still have to kiss the ass of anyone with pauldrons, but whatchagonnado?
Consult your local imperial administration office for further instructions if you believe you have a large hat.

Note that if your hat has frills, you may instead be a little girl. Should this be the case, instead contact your local shrine maiden.

Also, notice that helmets are not a form of hat, in fact, they are quite the opposite. While a Hat makes you more important, a helmet makes you less important. This can be simply seen in the armies of the Imperium, and indeed, of the forces of Chaos and the various Xenos as well, regular troops in squads have helmets while the squad's commander only goes out with either optics, comm equipment or hat to signify their rank or duty, but never a brain cage. The only exception is that they need it in extremely hazardous environment. This shows a clear social hierarchy in head and shoulderwear:
Helmet < No helmet < Hat < Pauldron + Helmet < Just Pauldron < Pauldron + Hat

Orkz have embraced this human custom. Eldar say that they had mighty and noble hats millions of years before the first early hominid put rocks on their heads. If one is of La or O rank in the Tau Empire can often be determined by his/her headgear. Hell, even Tyranids wear hats. And, of course, the Hive Tyrant has the biggest hat of all, therefore is leader. Even the Necrons in the wake of their latest update have taken to the habit of bolting down hats onto their metal skulls.

Take note that no-one has ever been seen as so important as to have Pauldrons AND a Hat, not even the Empra. Only the Classy Marines are given the utmost honor of donning a hat in tandem with their pauldrons for optimum classiness(although it should be noted that the rank and file classy marine has pauldrons, a hat and a helmet).

Few people know that were GW to actually move the turgid plot of 40k along, it would be revealed all the races are in fact fighting for a cargo ship full of hats.

WHAT THIS ISN'T TEAM FORTRESS 2