This project already has a DPL .
Check just above the Magic Window and you will see that notation.
Take a look at the Listeners Wanted Forum
viewforum.php?f=21
You will see several projects at the top that are looking for proof listening help.
Also check the New Project Launchpad and look for those with a tilde at the beginning of the subject line. Most of those will be open to a new proof listener (check the forum message because some one may already have volunteered. viewforum.php?f=28