Within one yard

The phrase within one yard recurs in GURPS discussions, and some confusion exists as to its context and meaning, given that 1 yard describes both:
#the distance between two opposite sides of 1 hex
#the distance between the centers of 2 hexes
Enemies in adjacent hexes are respectively 1 yard (3ft) apart if considered to be in the middle of their hex, but 0-2 (0-12ft) apart if perceived as able to vary at any point within the hex.
Examples
*2010 Kromm http://forums.sjgames.com/showpost.php?p=927077&postcount=6 "Must be adjacent (next hex or within one yard)."
Category:Rules