The IL13P-S is a C14/C20 IEC dual locking power connector that is able to prevent accidental disconnection ... This ensures compatibility with a wide range of standard non-locking C13 socket outlets ...

The problem with the connector type is its size. The C14 inlet, which is used to accept the C13 connector, is too deep to be feasibly included in thin computing deices. That's why Apple doesn't ...