What is BSD-style checksum file?

The format of HashSet (checksum file) commonly used on BSD-Unix systems.

Most advanced of plain text checksum file formats. Unlike of MD5SUM, which allows to use only MD5 and SFV, which allows to use only CRC32 checksum calculation algorithms, the BSD-style format allows to use any checksum calculation algorithm - CRC32, MD5 or SHA-1, for example.