Hello is a bridge convention used for intervention over an opponent's 1NT opening.
The name of the convention is derived from the names two of its inventors, Jerry Helms and Bill Lohmann.
Jerry Helms had previously co-developed "Helms", similar to the Cappelletti convention and saw this as an improvement to that convention.
[1] Helms considered that using 2♣ to show a major used up no bidding space and therefore lost the preemptive value typically attached to bidding major suits.
[2] It features the following calls: By design, in many cases, the advancer will become declarer, thus placing the strong 1NT hand on opening lead.