gml:axisDirection is the direction of this coordinate system axis (or in the case of Cartesian projected coordinates, the direction of this coordinate system axis at the origin).Within any set of coordinate system axes, only one of each pair of terms may be used. For earth-fixed CRSs, this direction is often approximate and intended to provide a human interpretable meaning to the axis. When a geodetic datum is used, the precise directions of the axes may therefore vary slightly from this approximate direction.The codeSpace attribute shall reference a source of information specifying the values and meanings of all the allowed string values for this property.
<element name="axisDirection" type="gml:CodeWithAuthorityType"><annotation><documentation>gml:axisDirection is the direction of this coordinate system axis (or in the case of Cartesian projected coordinates, the direction of this coordinate system axis at the origin). Within any set of coordinate system axes, only one of each pair of terms may be used. For earth-fixed CRSs, this direction is often approximate and intended to provide a human interpretable meaning to the axis. When a geodetic datum is used, the precise directions of the axes may therefore vary slightly from this approximate direction. The codeSpace attribute shall reference a source of information specifying the values and meanings of all the allowed string values for this property.</documentation></annotation></element>