"Players who master all the military uniforms during the Rendezvous at the Pentagon event will earn the grand prize Government Secrets armor mastery item. The Grand Prize will only be given to players who master all three levels of all three gifts. For the first time, players will have the incentive to repeat the event after achieving the Gold Mastery Items, so that they can accumulate multiples of items. Collecting 100 military uniform gifts will award a special achievement."
"Q: When does this event end?
A: A deadline hasn't been set yet.
Q: How many multiples can I get?
A: Once you've earned the Grand Prize item, your ability to collect multiples of the 3 Mastery items will unlock.
The current best strategy is to collect just enough uniforms to accomplish the first Gold Mastery item for each uniform and then wait until you've collected the Grand Prize. Then you can resume collecting other uniforms. It is possible to have multiple Gold Mastery Patrol Dolphins, but only 1 either Bronze or Silver Mastery Patrol Dolphin are allowed to exist at a time. Once you have a second set of Gold Mastery items, you will receive a second Grand Prize item.
Q: When will the 100 Uniform achievement become available and how can I track my progress?
A: The 100 Uniform achievement will become available once the Grand Prize is available. Until then, only 21 of each uniform can count towards your total."