T G C G T WR SB QB WR RB On the left are represented the more traditional and descriptive terms "end" and "slotback" (SB). The latter is for a position that would be labeled "FL", except that the back is in a "slot" between tackle and end (instead of outside of the end), here illustrating a double "wide slot" formation. (It is wide because the end is fully split, rather than merely flexed—see above.) There being no tight end, there seems to be no need to label either end as split; both are. But on the right, the slotback and end positions are merely labeled as wide receivers. The single running back here is shown to one side of the center-quarterback combination, but that "ace" RB could as well be directly behind them. In some cases, the specific terminology of certain coaches has made its way into the general parlance. Coaches, having no motivation to publicize their plans, usually adopt cryptic codes for certain positions, using letters, numbers, or short names for their convenience. One set of designations which has been making the rounds, as of this writing on Web sites, purporting to explain football is the letters X, Y, and Z to designate receivers. It is doubtful that many coaches agree on the use of these terms to designate specific positions consistently from play to play, and those letters do not seem to enlighten but only to obscure. (One manual for football spectators, in the 1960s, explained that someone calling offensive plays in the huddle would point to primary, secondary, and tertiary receivers while giving them those letters; those designations would vary depending on the play, not on the positions those receivers occupied.) However, one such letter designation has caught on recently: "H-back", illustrated in the offensive formation below: E T G C G T E QB WB HB RB Here the H-back is represented by the symbol, appropriately enough, "HB". The H-back position is like that of the "wingback deep" position previously described in a version of the single wing formation, and here is shown behind a wingback to emphasize that, although more often the H-back and wingback, if there is one, are on opposite sides of the set. It is possible to say the abbreviation "HB" is already taken up by the halfback. The H-back does occupy a position about the same as the halfback in