95% or more of the record-type definitions in practice are supposed to be nongenerative. The R6RS syntax, however, makes generative record-type definitions the default and needs an extra clause (nongenerative) to override this default.
We can change the R6RS version of `define-record-type' in SRFI 237 so that non-generativity becomes the default. For the few cases, generative record types are needed, a clause (nongenerative #f) must be added. The SRFI 9 version of `define-record-type' would still create generative record types. We can't change this in SRFI 237 unless we want to abandon R7RS Small compatibility (slightly). What do you think?
