The Moderated Private Discussion default List Type is used for small, private discussion forums where subscribers are allowed to post messages without moderation but messages from public senders are moderated. Because this List Type moderates public messages, it is more open to public posts than the Closed Private Discussion List Type, which rejects public posts outright. These two List Types are quite similar because subscriber posts are not subject to moderation, so once a user is subscribed, they can post messages directly to the list. Use this List Type when the benefit of allowing public posts justifies the cost of moderator intervention.

This default List Type allows small, private discussion groups to conduct ongoing conversations without moderator intervention. It is well-suited to the exchange of potentially sensitive information, especially if new subscribers are added by invitation only. Mailing lists that post subscriber messages rather than sending them for moderation are more vulnerable to spam than mailing lists that moderate all messages, so the number of subscribers is usually kept relatively small.

The Moderated Private Discussion uses the -mOuY combination to control posting access, so subscribers and moderators are allowed to post directly, but messages submitted by public senders are moderated.

Access is deliberately restricted in mailing lists based on the Moderated Private Discussion List Type in the interests of preventing spam. Users can't subscribe via email so the subscription process is handled exclusively through webtools. The Web Availability setting for mailing lists based on this List Type is usually set to 'Subscribers Only' to keep the list private.

Archive access is somewhat dependent on the Web Availability setting, since a user has to be able to access the Mailing List Home page in order to see the link to the list archives.