> On Oct 26, 2020, at 1:43 PM, Wietse Venema <wie...@porcupine.org> wrote: > >> A suffix looks like a good solution to me. > > On second consideration, I think I'll go for "uid:".
Yes, indeed ":" is the natural suffix, or prefix. But, when used as a suffix, postmap issues a warnings about needing to run it as postalias on files that look like aliases(5) files: $ cat /tmp/xyzzy 12345: a...@example.com $ postmap btree:/tmp/xyzzy postmap: warning: /tmp/xyzzy, line 1: record is in "key: value" format; is this an alias file? And does not complain when the key is ":12345", so the prefix form is likely better... -- Viktor.