extraneous locallockfile

Forgive me if this is a FAQ, but I have looked everywhere I can think
of. Why is each record in my logfile begun by a line

procmail: Extraneous locallockfile ignored

no matter whether the first line of the corresponding recipe in
.procmailrc contains a trailing colon or not? 

--
 Michael D. Harnois, Redeemer Lutheran Church, Washburn, IA
 mharnois(_at_)sbt(_dot_)net  aa0bt(_at_)aa0bt(_dot_)ampr(_dot_)org
 "Few sinners are saved after the first 20 minutes of 
  a sermon."  --Mark Twain