This is more a clarification than a decode, but it seems apparent that when Q uses the term "1-99", Q is referring to open air channels 1-99, aka the mainstream media.
So Class 1-99 means classified docs regarding uses of the mainstream media.
Keep in mind that the media is about manipulating people, not informing them. It is a weapon under direct control of our hidden enemy.
Declass 1-99 will probably be the event that wakes up the public by releasing official documents that the media has been used to manipulate the public. This will probably expand on what is available - i.e. Operation Mockingbird - but more like Mockingbird x 1000.
My guess is this event will happen shortly after Trump is confirmed another 4 years. It will need to happen to calm the public and prevent a civil war. The people will need to know that the media has been lying to them - and the media needs to be the one to say it.
