The "E" in E-one stands for "enlisted" when the "1" implies the paygrade for that situation. The opposite spend categories are "W" for warrant officers and "O" for commissioned officers. Some enlisted paygrades have two ranks. Britannica Dictionary definition of RANK 1 [extra rank; most rank] : having a robust, https://www.seoclerk.com/Link-Building/371800/GIGA-SEO-PACKAGE-POWERFUL-BACKLINKS