Since the old link we always used to link to is dead, I figured I'd go ahead and explain what "Survival Infection/Flood" means over here instead:
If you want your map to be played in a BIOC lobby, the map has to be a Survival Flood map. Survival Flood is a term used to describe Flood maps that use the classic "Zombie vs Human" way of playing and uses the Flood gametype to its full potential, promoting Strategy, Management, Teamwork and Survival. Mini-games using the Flood gametype are not considered Survival maps.