Though users generally comment into the same project as the article they are reading, by default it is possible to comment to any project where the user has Comment permissions.
This setting determines whether the user will be able to select alternative projects when commenting with the Article Editor or inline comment form.
If set to "Comments Can Be Posted to Any Project," users will be able to use the Project selector to choose to post the comment to another project where they have author permissions.
Disabling Comments Entirely In a Given Project: If you want to disable commenting entirely within a given project (generally, wiki style projects used for scenarios like documentation), set this project to its "No" setting (Comments Cannot be Posted to Any Project) and Deny comments in the Permissions for the moderation project.
