This counts how many multicast groups on the device were configured statically by an administrator rather than learned dynamically via IGMP joins. An admin doing a periodic cleanup of always-on multicast entries would use this count as a starting checklist size, then walk the group table filtering for static(1) type entries specifically to review whether each one is still needed. A steadily growing static count over many configuration changes, with no corresponding removal process, would be a sign of accumulating configuration debt worth auditing.