Black beret
Appearance
The black beret was the headgear for the US Army Rangers, and is for the Russian and USSR Spetsnaz units. It is traditionally associated wtih special forces troops.
In the US, the term black beret (akin to green beret being linked to US army airborne special forces) was linked to the Rangers, but General Shinsheki changed them to tan/brown berets, with black berets being for all US army troops.