call-up

call-up
n (US draft) [U, C esp sing 尤作单数]
summons for military service （服兵役的）徵集令, 徵召令
    receive one's call-up 收到徵集令
    [attrib 作定语]
young men of call-up age 适龄应徵的年轻人.

牛津英汉双解词典