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+GML 3.1.1 Schema Package Readme
+
+The schema package contained in this directory is the normative GML
+3.1.1 schema set as approved by the OGC membership in May 2005. This
+version corrects a number of errors in the GML 3.1.0 schemas that
+prevented validation.
+
+Reason for Changes: The XML Schema for GML 3.1 fails to validate using
+several of the most popular XML processing software applications.
+
+Four sets of errors have been found in the GML 3.1 Schema, with
+corrections applied as described:
+
+1. the content model for "metaDataProperty" is non-determinstic: you
+can't have a choice group containing <any> with anything else 
+	- delete _MetaData from the choice group
+
+2. membership of the _timeLength, _Value, _ScalarValue,
+_ScalarValueList substitution groups relies on an interpretation of the
+XML Schema specification which is not uniformly accepted
+	- replace with an explicit <choice> groups 
+
+3. axisName (type="string") in grids.xsd clashes with axisName
+(different type) in coordinateSystems.xsd 
+	- Remove the latter, use the gml:name property instead
+
+4. a "derivation-by-restriction" pattern used widely throughout the
+schema has a cardinality constraint (minOccurs="0", and sometimes
+maxOccurs="unbounded") applied to a "property" element in a base type,
+where the property element is the head of a substitution group; in a
+type derived by restriction in which one or more members of the
+substitution group is selected, the validation procedure described in
+the W3C XML Schema specification requires that the validation
+constraint appear on a <choice> container element, rather than on the
+substitution group member element
+	- move the cardinality constraint up to the <sequence>
+	  container element
+	- remove unnecessary derivation-by-restriction chains,
+	  particularly concerning derivation of property elements
+
+As this pattern is used pervasively in GML, there are numerous changes
+in almost all of the schema documents.
+
+The revised schema has been tested with Xerces-J, XSV, .NET, MSXML and
+no validation errors are found. 
+
+http://schemas.opengis.net/gml/3.1.1/
+
+2005-08-11
+