Q: Why does Hesiod have passwd entries for common services?

Answer

Particularly observant system administrators may have noticed that Hesiod has entries for several common services:

$ hesinfo www passwd
www:*:6623:101:Unprivileged W User,,,:/mit/www:/dev/null
$ hesinfo uucp passwd
uucp:*:66:101:Administration UUCP,,,:/mit/uucp:/usr/lib/uucp/uucico
$ hesinfo discuss passwd
discuss:*:32000:101:Discuss System,,,:/mit/discuss:/bin/csh

These entries date from long-dead versions of Athena, and can be ignored. On modern versions of Debathena, the operating system will take care of automatically allocating unused UIDs for system services. System administrators can of course change the UIDs as they see fit, but there is generally no need to do so.