This was cross-posted on perlmonks and what seems like a reasonable respnse was given there:
An option to specify whether or not to use a user field. -- H4sICNoBwDoAA3NpZwA9jbsNwDAIRHumuC4NklvXTOD0KSJEnwU8fHz4Q8M9i3sGzkS7BBrm OkCTwsycb4S3DloZuMIYeXpLFqw5LaMhXC2ymhreVXNWMw9YGuAYdfmAbwomoPSyFJuFn2x8 Opr8bBBidccAAAA= -- MOTD on Prickle-Prickle, the 62nd of The Aftermath, in the YOLD 3170: [sarcasm included]
