When Alfresco makes permission checks, ACEs are considered in order with the lowest position first. Deny entries take precedence over allow entries at the same position. Once a deny entry is found for a specific authority and permission combination, any matching ACE, at a higher position from further up the inheritance chain, is denied. A deny for one authority does not deny an assignment for a different authority. If a group is denied Read permission, a person who is a member of that group can still be assigned Read permission using another group or directly with their person userName. However, if an authority is granted Read (made up of ReadContent and ReadProperties) and the same authority denied ReadContent, they will just be granted ReadProperties permission. The administration pages of Alfresco Explorer and Alfresco Share do not expose deny.