In general, NSmen who do not hold any key appointments may be posted to the MINDEF Reserve (MR) holding list once they have fulfilled a minimum of 7 High Key training with 10 ORNS years. However, while in MR, NSmen may still be called up, based on the needs of the SAF, as they remain liable for service up to the age of 50 for Officers and 40 for WOSEs.  NSmen may contact the unit and unit commanders directly or call the NS Contact Centre (1800 3676767) for assistance and further details about call-ups.