# VFK - Czech cadastral exchange data format

VFK driver can read data in the Czech cadastral exchange data format. The VFK file is recognized as an OGR datasource with zero or more OGR layers.

Points are represented as wkbPoints, lines and boundaries as wkbLineStrings and areas as wkbPolygons. wkbMulti* primitives are not used. Feature types cannot be mixed in one layer.

## Datasource name

Datasource name is a full path to the VFK file.

## Layer names

VFK data blocks are used as layer names.

## Attribute filter

OGR internal SQL engine is used to evaluate the expression. Evaluation is done once when the attribute filter is set.

## Spatial filter

Bounding boxes of features stored in topology structure are used to evaluate if a features matches current spatial filter. Evaluation is done once when the spatial filter is set.

## References

- OGR VFK Driver Implementation Issues
- Czech cadastral exchange data format documentation (in Czech)