I don't think it's an Army specific regulation. . .it's specific to the award. For instance, I earned the GWOT-E and the ICM . . . but from two separate deployments. On my first deployment, during the transition phase, I was given the option of selecting either the GWOT-E or the ICM. I chose the GWOT-E, as I was told it would be going away for deployments to Iraq and Afghanistan due to there being awards issued for those specific deployments. For my second deployment, there wasn't a choice, the ICM was the only award given In addition to the GWOT-S and all the other chest candy that comes along with a deployment.