Welcome to the space marine base.
We always need warriors for this job. We need human or human hybrids for this job. Want to be on the patrol unit? Then sign up for it. We aint stopping you but we will question you so be prepared.
and the most important one
At least know one doom testament
Dont worry if you know only two of these things then you can still come in. Welcome aboard, your future and humanity's future awaits...