Everyone signs up for eight years of call up... Some serve two active - 6 inactive.
That is correct....I enlisted for 4+2 (got a guarunteed promo out if bootcamp and and skipped from E2 past E3 straight to E4 afyer finishing my 1st sonar school.... 5 months from E1 to E4....)
I was on hook for another 2 yrs inactive reserves (got the pink ID card atill) after that.
At the time (enlistment ended 8-4-92) the rules basically said tjey had to reinstate the draft beforr they called me back....barring a critical need for my specific job.
When I served (68-76) it was minimum 2 years active, 4 reserve.