Originally Posted by findark

Economy Plus fares, which are published systemwide (or near-to) domestically as a differential fare to regular Economy and a primary rbd of B. These fares have an 'I' in seventh position (which usually identifies the differential type of a domestic fare), and are sold specifically to "bundle" Economy Plus access as part of the coupon value itself. So far, United has not marketed them, but searching for B class on a domestic route should yield this as the cheapest fare which confirms in B class.

Originally Posted by jsloan

Anecdotally, they appear to be creeping in internationally as well.