Access to some areas is entirely based on roles. For example, if a news category "Jr. News" allows the Parent role to see its news, then all Parents can see "Jr. News". While it is possible to create a role called "Parents of Jr. School" and assign it the Jr. School parents, it would have to be manually updated on a regular basis. A "smart role" could use conditions based on a list (maybe even an advanced list) and automatically update who should be included.