Transparency attributes are applied from larger scopes inward. For instance, if a type is marked as entirely security critical, ...

Transparency attributes are applied from larger scopes inward.  For instance, if a type is marked as entirely security critical, than all methods introduced by the type will also be security critical.  Members should not have transparency annotations which conflict with larger scoped annotations, as these smaller scoped annotations will be ignored by the CLR and can be misleading during a code review.  Methods not introduced by their type, such as virtual methods being overridden from a base type or interface methods being implemented, do have their annotations considered under the level 2 security rule set and are not considered by this rule.