What Can They See?

External contributors can't see everything in the community because they are limited to the content in their groups and a few other restrictions.

External contributors can see:

External contributors cannot see:

Spaces or projects besides those in their groups.
Community Overview page found when you click Home.
Global or public content, such as status updates, public bookmarks, or public documents and discussions.
Apps, but they can see images embedded by apps within their groups.

What's Unavailable to External Contributors?

External contributors see the community pretty much the same way a standard user with the following exceptions:

Update their status.
Create public discussions and documents.
See and work with private messages, only unauthorized messages are seen.
See or use Jive Apps. External contributors can not see or launch Apps or App Actions.
Use Connects Services. External contributors also cannot see Connects Services in their user's Preferences page.
See or use the Tools page, so they can't download modules like Outlook, Office and Jive Anywhere.
Access public external URL bookmarks or social bookmarking. External contributors can create and view internal bookmarks of Jive content.
Become group owners.