Switch discovery doesn’t always discover hints to a fabric’s name, and lacking burrowing into the switch in a wholly instrusive and needs-root-access manner, some switches get tossed into “VirtualFabric”. Removing and re-adding switches, I found a user having to re-specify these repeatedly, and forgetting whether it was done.

When I forget things, I get worried. What if someone else does?

…so I added a check in PHC for ProbeSW in Virtual Fabric to catch where the user has not yet named a fabric.