C# Language Specification

Interface modifiers

An interface-declaration may optionally include a sequence of interface modifiers:

interface-modifiers:
interface-modifier
interface-modifiers interface-modifier

interface-modifier:
new
public
protected
internal
private

It is a compile-time error for the same modifier to appear multiple times in an interface declaration.

The new modifier is only permitted on interfaces defined within a class. It specifies that the interface hides an inherited member by the same name, as described in §10.3.4.

The public, protected, internal, and private modifiers control the accessibility of the interface. Depending on the context in which the interface declaration occurs, only some of these modifiers may be permitted (§3.5.1).

2.