The Database Standards Subcommittee of the AAPG Committee on Computer Applications has developed the AAPG-A data exchange format. The AAPG-A data exchange format is intended to help in the transfer of interdisciplinary geologic or petroleum information (such as lithologic descriptions, stratigraphic data, well-history and production information, and data descriptors like sample locations) by establishing a public, easily accessible, and highly versatile format. The AAPG-A data exchange format consists of at least three files: a header block file, a data block file, and a termination record file. The header block file consists of a series of format records that completely define the records in the data block file. The termination record file completes the volume. The AAPG- data exchange format is intended to be self-defining and implementation independent. It is intended for use by the general geologic community and is based on concepts currently implemented in the petroleum industry.