तेषामन्यतमस्यानयने बहिरेवोच्छुल्को विक्रयः ॥ कZ_०२.२१.२३ ॥
teṣām anyatamasya ānayane bahir eva occhulko vikrayaḥ
When any of those (restricted items) are brought in, their sale shall take place only outside (the frontier/post), and it shall be duty-free.
The state channels sensitive goods to controlled points and limits inland circulation while still enabling regulated disposal and intelligence/monitoring at the frontier.