The short answer is that these are the security tables...
If I remember right, the JFORUM_ROLES maps permissions to groups. Permissions can be "global", e.g. perm_administration, or they can be specific to some other area, e.g. perm_category to see a category or perm_forum to see a forum.
If the permission applies to a sub area. The JFORUM_ROLE_VALUES table gets used to identify the subarea. E.g., the Role_Value field in the record that matches the role_id, gets the id of the category or forum that the permission applies to. [originally posted on jforum.net by monroe]
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