Vendor Specific capability in WFS 1.1.0

We are implementing a WFS 1.1.0 at our end based on OGC specification documents (04-094_Web_Feature_Service_Implementation_Specification_V1.1) and the schemas avaialble at opengis.schemas.net for WFS 1.1.0. We want to add a vendor specific capability element to our service in which additional capability of WFS published. 

As per the implementation specification document, under section 14.3.4 it is clearly mentioned how request can contain vendor specific parameters and the corresponding server behaviour. At the same section, it is also mentioned that how any service may choose to publish its vendor specific capability in the capabilityXML and for which "the VendorSpecificCapabilities element must be redefined accordingly. Additional schema document may be imported containing the redefinition."

Now coming to the dilemma, the schema present as opengis.schemas.net for WFS1.1.0 doesnot contain any such element so how are we supposed to include it? Whereas, the schema of WFS1.0.0 has this element defined in its schema. Can we use that element schema and simply include it in the WFS 1.1.0 schema? If yes, will it not violate the OGC compliance while we test this implementation? Should it be treated as a bug in the schema document?