diff --git a/specs/bls_signature.md b/specs/bls_signature.md
index d119c4499..3fe1bcc0e 100644
--- a/specs/bls_signature.md
+++ b/specs/bls_signature.md
@@ -1,6 +1,8 @@
 # BLS signature verification
 
-**Warning: This document is pending academic review and should not yet be considered secure.**
+**Notice**: This document is a placeholder to facilitate the emergence of cross-client testnets. Substantive changes are postponed until [BLS standardisation](https://github.com/pairingwg/bls_standard) is finalized.
+
+**Warning**: The constructions in this document should not be considered secure. In particular, the `hash_to_G2` function is known to be unsecure.
 
 ## Table of contents
 <!-- TOC -->