High Elf models with this special rule can make supporting attacks with one extra rank than normal. This is cumulative with any other special rule that allows a unit to fight in extra ranks. In addition, when shooting, all High Elf models with this special rule fire in one more rank than normal (if the unit chooses to Volley Fire, this will normally mean that all the models in the front three ranks, and half the models in the fourth and any subsequent ranks, are allowed to shoot). This is cumulative with any other special rule that allows a unit to shoot in extra ranks.