Around here, it is the commonest way to call eliminations, so it is sort of a default. Similarly, "back-left," "center-fifty" and "your mirror" all form a pretty common vocabulary. This sort of thing is nice for those who play with multiple teams, as well as dim players who have a harder time learning calls. Some of the best call systems I have heard have been abandoned due to laziness and prevalence of certain customs like "g" counts, which make it less necessary to master a new protocol every time you play for a diferent team.