I have my devices set to name based on ${HostName} ${MACAddress}

This works fine for the Windows workstations but for the Linux Primary
and satellite servers I get the follow error every time they refresh:

Device name contained illegal characters, changed to zcm1
00_1e_67_2b_ef_80 while attempting to register host: zcm1

As far as I can tell, this is only cosmetic and doesn't cause any
problems. This has been happening since whatever update (11.1?) allowed
MAC addresses in device names. I just built a new zone (11.2.2) with
only 1 primary and no workstations and still get the error.

I'm not going to burn a SR over this but has anyone else seen this
error? I'd like to stop it from showing up in the message logs if possible.