This object's DESCRIPTION field in the source is empty, so its exact intended meaning isn't documented beyond its name and default value of false, but based on the OSPF passive-interface convention and its pairing with eltOspfIfPassiveList, it appears to set a device-wide default for whether new OSPF interfaces are treated as passive (not sending routing updates). An administrator would use a setting like this to decide the baseline behavior for interfaces not explicitly listed elsewhere. With the documented default of false, interfaces would default to actively participating in OSPF adjacency and update exchange rather than being silently passive.