Since EHV-1 is a common virus in horses, it is recommended that all horses be vaccinated at least once a year. For horses congregating at shows and competitions, more frequent vaccinations may be recommended.
Enfilade and defilade. Enfilade and defilade are concepts in military tactics used to describe a military formation's exposure to enemy fire. A formation or position is in enfilade if weapons fire can be directed along its longest axis.
DEFCON levels describe the state of readiness for the US Armed Forces, with 5 being the lowest (i.e. normal readiness) and 1 being the highest (nuclear war imminent).