At the beggining of 'The Extraction'(or pretty much anyone of the 3 Co-op Strike missions) when both of you spawn, you will be in a safe zone with a shooting range on your left and an armoury next door with a drop zone nearby. Beside that is a innocent whiteboard on a small wooden stage. You might have breifly looked at it or did some planning with your partner. However, this white canvas hides something suspicious...

▲ The map overview is simply a mask to it's true meaning

If you were to ask (or purposely) stab/shank your friend with your knife of choice in front of the board, you would find that the blood would stain it and make the map look different
It looks much cooler now

Now, if you continue to 'murderously' attack your partner on the right side of the board, you will see suspicous blue-tinted numbers and words on the board that were hidden before:
Messages revealed by blood, weird...

200100? A code? What's on the top right of the board?

To reveal the second hidden words, ask (or threaten) your partner to jump continuously while you stab/shank mercilessly at him/her, you will see this:

CFL 55 DI, and also some hidden cross marks not there before. Suspicious...

I've checked the left side of the board, but we could find nothing. Just blood stains.

Although we don't really know what these hidden messages mean, here are a few things that it could be:

• Something to do with other missions in the Gemini Campaign
  
• Possibly related to the story of Operation Wildfire
  
• Unlocks an easter egg
  
• Nothing

Let me know if you could figure out what these messages could mean on the comments below. Post this guide on Reddit if you want and make sure to share this guide to your friends!

Happy Hunting

I like to say thanks to my partner, chef for coincedentally finding this with me and allowing me to stab him for science

Rip Operation Wildfire (I mean the Phoenix Compound missions), you will be missed
2016-2016