OPSEC is a term used by the Military which means "Operational Security".

Remember the "Loose Lips Sink Ships" line from WWII?  Applies just as much today...and tomorrow.

Something as important as Operational Security needs to be referenced from the source, not a self-proclaimed expert.  Every now and then we get an 'expert' (for some reason it is always a spouse of a Military person) who not only knows everything about security, but is more than willing to post all kinds of advice.  BEWARE THE SOURCE.  If posting helpful advice, please state your background/sources/experience/certifications to provide material and guidance.

Try reading these for some help:

http://www.defendamerica.mil/articles/a021202b.html

http://www.ioss.gov/bulletin.html

http://www.army.com/articles/item/3305

Of course, Army Regulation 530-1 is a great source, unfortunately it is classified....(big help, huh?) (it is designated FOUO For Official Use Only, so it isn't supposed to be posted on a web site...sorry)

THE best OPSEC rule for this forum is "If in doubt, leave it out!".  Let's keep the troops safe, supported, and get them back alive.