and flag officer positions in the unified and specified combatant commands, and up to three general and flag officer positions on the Joint Staff, as positions to be held only by reserve component officers who are in a general or flag officer grade below lieutenant general or vice admiral. Each position so designated shall be considered to be a joint duty assignment position for purposes of chapter 38 of this title. (B) A reserve component officer serving in a position designated under subparagraph (A) while on active duty under a call or order to active duty that does not specify a period of 180 days or less shall not be counted for purposes of the limitations under subsection (a) and under section 525 of this title.