This feature is not on a current W3C standards track, but it is supported on the Firefox OS platform. Although implementations may change in the future and it is not supported widely across browsers, it is suitable for use in code dedicated to Firefox OS apps.
isDisplayNetworkNameRequired is a read-only property that indicates the Network name must be a part of any displayed carrier name.
var required = navigator.mozMobileConnection.iccInfo.isDisplayNetworkNameRequired;
Return a boolean.
Not part of any specification.