Type "Y" appliance

[Nick]

Its an IEC 60050-442 1998 (section 442-01-35) standards reference as to how the power cord is fitted internally:

• Type Y
  a method of attachment such that the flexible cable or cord can only be replaced with the aid of special purpose tools normally available to the manufacturer or his agent
  

For completeness, type X doesn't require any special tools etc., and type Z means that replacing the cable would require the destruction of the device.