it means that your reservist unit is on full
fbo mobilisation standby for a certain period. once activated,
u r to report to your designated mobilisation centre, usually ur
reservist camp.
codewords will be flashing on the tv if it is a open mob.
u will be contactly via call if it is a slient mob.
more info: http://www.mindef.gov.sg/imindef/mindef_websites/topics/nsmen/opsready/mobilisation.html
if u even bother to search for answers using the search function
there ARE the same topics over the time.