Signature

If the BOD is to be signed the signature element is included, otherwise it is not.
Signature supports any digital signature that maybe used by an implementation of OAGIS. The qualifyingAgency identifies the agency that provided the format for the signature.

This element supports any digital signature specification that is available today and in the future. This is accomplished by not actually defining the content but by allowing the implementation to specify the digital signature to be used via an external XML Schema namespace declaration. The Signature element is defined to have any content from any other namespace. 

This allows the user to carry a digital signature in the xml instance of a BOD. The choice of which digital signature to use is left up to the user and their integration needs.