The following metadata items have a special meaning for vector layers.
- LAYER_TYPE: Can be UNKNOWN (implicit default), WHOLE_POLYGONS (all shapes are closed polygons that represent a
region, possibly including internal rings), TOPO_ARCS (topological arcs layer), TOPO_NODES (topological nodes layer),
TOPO_AREAS (topological areas layer), POINTS (all shapes are one vertex points), ARCS (all shapes are multi-point arcs), or
TABLE (no vertices; this layer is pure attribute information). For more information about the requirements of topological layer
requirements, see the Topology definition.
- ARC_REF, NODE_REF and AREA_REF: A set of topological layers are grouped with each other with these metadata entries.
A detailed explanation of the layer reference naming convention can be found in the general metadata topic.
- XXX_FieldID: This metadata identifies the attribute field on this layer that is used for a particular renamable system attribute
role. For a list of system attributes and their roles, see System attributes. The value can be the name of a field or its zero-based
field number. For example, a REPCode_FieldID value of Attribute would indicate that the field named Attribute should be used as
the REPCode for this layer.
- LONG_FIELD_NAME_n: The long name for the indicated field. The long name is preferable for display to the built-in short field name.