Shuttle Certification Question

Prior to the CAIB, did *anyone* ever talk about "certifying" Orbiters,
or is that entirely a post-Columbia phenomenon? Because I can't
recall it in history, and that includes eleven years in Downey in the
eighties.

The reason that I ask is that I've acquired part of the appendix on
the subject on a recent study that NASA did, and wonder if they just
came up with the "certification" language to satisfy the CAIB's
question about flying past 2010. I've never before heard of a
"certification reverification." What is being described here is
basically a reverification.

I've posted the text, with a figure for schedule post 2010, at my
blog.

http://www.transterrestrial.com/?p=16160