Ribbons

As each description says : 
Xenophobe : complete 100 HMX games where soldiers win.
Lead the invasion : complete 100 HMX games where mutans win.

Is a website traker on webpage : https://crossfire.z8games.com/events.html -> click "Ribbon Tracker" 
So you can check your progress, but you need to complete the task ( one or both , as you wish ) in 30 days, as the tracker reset and you need to start over if you can't complete in the given time.

I don't know how many players are needed but you can find as you play and check web tracker ( usually can take up to 20 minutes to update).

@gglugglugg
Send a support ticket and they can see what is about.