Call-ups are typically associated with the military, where soldiers are summoned to active duty. Antonyms for this term might include release or discharge, which would indicate that the soldiers are no longer required to serve or report for duty. Alternatively, other antonyms for call-ups might include voluntary enlistment or recruitment, which would refer to soldiers who are joining the military of their own free will rather than being conscripted. In a broader sense, antonyms for call-ups might include things like freedom or independence, which suggest the opposite of being summoned to serve a particular cause or organization.