Domino 9.0.x/10.x, Traveler 9.x/10.x
First the groups (and mail-in databases) within the server names.nsf with a /* in the name. If you try to do this with the Notes client, it will pop up a warning indicating "Warning: It is recommended that the '/' character not be used in the Group Name". With a '/' in the name, the lookup results that are returned by Domino (lookup request from the client, received by Traveler, call to Domino), has the ListName in canonical format."
This document requests more options to prevent canonical names from being displayed in the Traveler device in this context