The Meaning of 5x5
The term 5X5 is rooted in the communications within military forces through WWII to mean "I understand you perfectly." The first number represented the Signal Strength of a radio communication, and the second number represented the signal clarity on a scale from 1-5 -- 1 being the worst; 5 being the best. Therefore 5 by 5 means the signal has excellent strength and perfect clarity - the most understandable signal possible. Five by five is the predecessor to the term "Loud and Clear" or "Lima/Charlie" used by military units today. It found its way into verbal slang, meaning "everything is good" or "everybody is well/good".
This is how we use the term at 5X5 Brewing Co. We hope everyone is good, and we know that all of our beers are of the best quality.