The real DESCRIPTION field here is just the auto-generated stub "Cisco UCS fabric:FcVsanPortEp:slotId managed object property", so it carries no real prose -- but the property name and its CucsFabricFcVsanPortEpSlotId type tell you what it holds: It holds the physical slot number this VSAN port endpoint's port lives in on the fabric interconnect. On fabric interconnect models with expansion modules, this field on this VSAN port endpoint distinguishes a port on the fixed base module from one on an add-in FC expansion card, which matters because expansion-slot ports are the ones an admin can physically add or remove. This VSAN port endpoint might report slotId 1, placing its physical port on expansion module 1 rather than the fixed base module.