Communication and Network Riser, CNR is a specification that supports Audio, Modem, USB, and LAN interfaces of core logic chipsets. This technology and the CNR slot was first introduced by Intel February 7, 2000 and was mainly developed by leading hardware and software developers who helped release the AMR (Audio Modem Riser) slot. In the picture below is an example of a CNR slot, which is labeled as "CNR_SLOT" on this motherboard.