16. Where the interests of Singapore so require, the President may, by proclamation, empower the proper authority to call out persons liable to render full-time service, operationally ready national service or regular service for mobilised service.
17. Where a proclamation under section 16 is issued, the proper authority may order —
that a person shall not be released at the end of his period of full-time service, operationally ready national service or regular service and that the person shall continue to render mobilised service; and
that a person liable for operationally ready national service shall report for mobilised service.
18. Every person liable for mobilised service shall upon a proclamation being issued under section 16 report for mobilised service and remain in mobilised service until discharged or released by the proper authority.