Controls whether this SDC entity maintains a mapping from System IDs to hostnames, used to populate objects like isisISAdjNeighHostname and isisISAdjNeighLanIDHostname and to show hostnames instead of raw IDs in PD logs; enabling it (default false) incurs a small memory/occupancy cost for maintaining the mapping database. An admin enables this when human-readable hostnames in adjacency tables and logs are worth the modest extra memory overhead, which matters more on memory-constrained platforms.