To help with collaboration, you’ll want to give your co-writers some more in-depth information about the screenplay you’re writing. You'll see that when you create a project, you're prompted to create a few documents:

Project Blog

General announcements, updates, or whatever musings you may have are just the thing for your project blog. Keep your writers informed and updated!

Guidelines

Got any rules or guidelines you'd like writers to keep in mind while working on the screenplay? Put 'em here!

Reference

Use this space to post anything that helps inform your script - outside links, information, that totally awesome list of the ten must-haves for your martial arts romantic comedy screenplay, etc.

Characters

This page allows you to create a central location for character descriptions. You can use this space to collaborate on your screenplay’s characters or just help build a reference to help enforce continuity.