This is the object's relative name (Rn) — just the last path segment of its Dn, the piece this ChassisParam instance contributes to its own address within the MIT tree. Each ChassisFeature can carry several tunable settings as separate key/value ChassisParam children — e.g. the wattage ceiling under a power-cap feature — so this is where the actual configured number, not just the feature's name, lives. For this kind of object the Rn is typically built from the same identifying value as its Dn's final segment, e.g. the tail end of `sys/chassis-3/chassis-feature-power-cap/param-wattage-limit`, so two sibling instances never end up with colliding addresses under the same parent.