diff --git a/docs/proof_mode.md b/docs/proof_mode.md
index a8e11f8d13de66161b43fcdfc5113751f54de88e..1d8c8e37d0fe844f7b35aa3e6047e35b5ded25cf 100644
--- a/docs/proof_mode.md
+++ b/docs/proof_mode.md
@@ -234,7 +234,8 @@ _introduction patterns_:
will fail. We provide an implementation of the hook using Ltac2, which works
with Coq 8.11, and can be installed with opam; see
[iris/string-ident](https://gitlab.mpi-sws.org/iris/string-ident) for details.
-- `%` : move the hypothesis to the pure Coq context (anonymously).
+- `%` : move the hypothesis to the pure Coq context (anonymously). Note that if
+ `%` is followed by a string, and not another token, a space is needed.
- `->` and `<-` : rewrite using a pure Coq equality
- `# ipat` : move the hypothesis into the intuitionistic context. The tactic
will fail if the hypothesis is not intuitionistic. On success, the tactic will