Lockrings are not supplied with Campagnolo sprocket cassettes, except with 11-up cassettes where a smaller lockring diameter is required, and with Record 8-speed.
11 speed cassettes are also supplied with lockrings.
HG10 freewheels for Dura-Ace 10 speed cassettes require CS-701 or CS801 lockrings. All other HG freewheels require a Shimano lockring.
See compatibility chart below for details.