  I present a summary of recent use of the Open Archives Initiative (OAI)
registration and validation services for data-providers. The registration
service has seen a steady stream of registrations since its launch in 2002, and
there are now over 220 registered repositories. I examine the validation logs
to produce a breakdown of reasons why repositories fail validation. This
breakdown highlights some common problems and will be used to guide work to
improve the validation service.
