Novatrooper

Novatroopers are Stormtrooper honor guards that are easily identified by their distinctive black and gold reinforced armor. As honor guards, Novatroopers are usually assigned to protect important locations of interest or to guard important dignitaries. Since Novatroopers are more skilled than the average Stormtrooper, they’ve also been utilized for commando missions, such as infiltrating enemy bases.

Aside from their reinforced armor, Novatroopers use the same equipment as their Stormtrooper counterparts, but are altogether more proficient at getting the most out of it. They’re considered to be better fighters, better marksmen, and better tacticians than the common Stormtrooper. =Sources=
 * Wookieepedia