During my years working for 5.11 Tactical I was constantly asked one question above all!
"What does "5.11" stand for?"
Is it a police call sign? A military code? Radio chatter? No...it's none of these.
5.11 Tactical's first pair of pants, the Tactical Pant, feature the trademark tactical strap and slash pocket design which were originally developed for rock climbing. '5.11' was a rock climbing difficulty where, at the time, 5.10 was the hardest climb with 5.11 being almost impossible however, occasionally someone would complete this climb (current climbs go to 5.15). Dan Costa, who took over 5.11 from Royal Robbins, who is one of the pioneers of American rock climbing, noticed the pants were extremely popular with the FBI. An FBI officer received the 5.11 Tactical Pants as a gift and they quickly became a staple around the academy and the rest, well...is history.
Top 10 5.11 Products at TacSource