This SRFI is withdrawn.

For the curious, the version with the changes that were to become the next draft is still at <https://github.com/dpk/srfi-262>. The current HEAD of the sample implementation, extensible-match, includes all changes up to this point.
<https://codeberg.org/dpk/extensible-match/commit/2a5834639666790bac14a89b05389eaea66c4d55>