Release 2.1 NaPTAN, & NPTG is a very minor release of NaPTAN 2.0It contains a very small number of additional corrections since the last dra ft release 2.0,which are listed below.   Revisions=++========The following is a list of the  changes in 2.1 Changes that may cause breakage in 2.0c implementations are marked with a ++     Started 2.1  2005/09/05 * 2005/09/05    - [NaPT_Stop-v2.1.xsd] Make StopPoint / Descriptor / Landmark and Street optional:       Applications shoudl no longer assume these are always present.    - Revised versions of NaPTAn 2.1, NPTG 2.1 and NPTG Discovery to reference the revised Stop package.    - Some documentation comments revised. * 2005/09/08    - [NaPT_Stop-v2.1.xsd] Add Annotated CoachRef to on street bus stop types, Allow OperatorRef on AnnotatedCoachRef * 2005 09 23  [Bug Report AIM - MF]    - [NaPT_journey-v2.1.xsd]        Correct Schema ID to be napt_journey-->  

 * 2006/11/07 
    - NPTG schema stated version level corected to be 2.1