PCT (Pacific Crest Trail)
One of the greatest treks the U.S.A. has to offer, the Pacific Crest Trail is a 2,659-mile hiking and equestrian route that runs from the U.S.-Mexico border (near Campo, Calif.) to the Canadian border at Manning Park in British Columbia. The PCT follows close to the high point of the Sierra Nevada and Cascade mountain ranges, 100-150 miles inland from the Pacific Coast.
PLB (Personal Locator Beacon)
A PLB is a last-ditch emergency device for those who travel into the wilds. By pressing a button, people in trouble can summon help through a network of satellite communication. PLBs also offer less dire features, such as tracking of individuals off the grid, one- and two-way messaging, and check-ins with loved ones back home.
PR (Personal Record)
Athletes in many sports like running and cycling keep track of their best efforts over a given distance or goal. They call these PRs.