diff --git a/preserves.md b/preserves.md
index c9f7f7d..543f476 100644
--- a/preserves.md
+++ b/preserves.md
@@ -1344,5 +1344,16 @@ explicit "I promise this is canonical" marker, like a BOM, which
 identifies a binary value as (first) binary and (second, optionally)
 as canonical. UTF-8 disallows byte `0xFF` from appearing anywhere in a
 text; this might be a good candidate for a marker sequence.
+((Actually, perhaps `0x10` would be good! It corresponds to DLE, "data
+link escape"; it is not a printable ASCII character, and is disallowed
+in the textual Preserves grammar; and it is also mnemonic for "version
+0", since it is the Preserves binary encoding of the small integer
+zero.))
+
+TODO: Remove the special short syntax for application-specific record
+label usage? Then perhaps 8x, 9x, Ax and Bx would work for Record,
+Sequence, Set and Dictionary, leaving Cx, Dx, Ex and Fx entirely free.
+
+TODO: Forbid empty chunks?
 
 ## Notes