the children of full-time, locally-hired employees of the Department of Defense in an overseas area if such employees are citizens or nationals of the United States; and

the children of a foreign military member assigned to the Supreme Headquarters Allied Powers, Europe, but only in a school of the defense dependents’ education system in Mons, Belgium.

In the regulations required by subsection (a), the Secretary shall prescribe a methodology based on the estimated total number of dependents of sponsors under section 932(2) of this title enrolled in schools of the defense dependents’ education system in Mons, Belgium, to determine the number of children described in paragraph (2) of subsection (a) who will be authorized to enroll under such subsection. The Secretary shall prescribe such methodology with the advice and assistance of the commander of the geographic combatant command with jurisdiction over Mons, Belgium.

If the number of children described in paragraph (2) of subsection (a) who seek enrollment in schools of the defense dependents’ education system in Mons, Belgium, exceeds the number authorized by the Secretary under paragraph (1), the Secretary may enroll the additional children on a space-available, tuition-free basis notwithstanding section 923(d)(2) of this title.