well not all markets have them... so it is not surprising for someone not to know about it...
before the advent of the NECA, ECA would refer to a market cluster. meaning, for instance, the individual markets of Modest/Merced, Fresno, and Visalia had an ECA option that allowed customers to travel between these markets without roaming, but we've had NECA for some time now (like 1 1/2 years or something?!?!) they also had intra market ECA in Texas, which the markets do not butt up against each other like ours do in CCV, and that is/was a major selling point against pocket... (hence the don't get stuck in a pocket advertising campain)