Where is "Hutton's Razor" first defined?

The earliest mention I can find is in 1998, in Section 2.1 of Hutton's Fold and Unfold for Program Semantics.

Hutton and Wright's 2004 "Compiling Exceptions Correctly" describes such a language. It does not use the term "Hutton's Razor" (nor would we expect it to) but it introduces this minimal language with sufficient motivation to imply there isn't prior art in mind for such a drastic approach. On the first coinage of "Hutton's Razor" to describe this language, I really have no idea...