Rule A10-0-1 (required, design, non-automated)
Public inheritance shall be used to implement “is-a” relationship.
Rationale
Public and non-public inheritance have a very different application and it shall be used accordingly. See: Is-a-relationship, Has-a-relationship
## See also
JSF December 2005 [8]: AV Rule 91: Public inheritance will be used to
implement “is-a” relationships.