B.4 Database Files
The database routines in the getXbyY() family (gethostbyaddr(), etc.) were originally designed (in the first Berkeley UNIX releases) as mechanisms for looking up information in text databases. A Windows Sockets supplier may choose to employ local files OR a name service to provide some or all of this information. If local files exist, the format of the files must be identical to that used in BSD UNIX, allowing for the differences in text file formats.