diff --git a/docs/erc7730-compiled-format.md b/docs/erc7730-compiled-format.md
index f6f63fb9..120e5846 100644
--- a/docs/erc7730-compiled-format.md
+++ b/docs/erc7730-compiled-format.md
@@ -232,6 +232,9 @@ formatters require scheme, plaintext type and plaintext formatter roles.
 Unknown kinds, roles, flags or invalid kind/role/source combinations are
 rejected. Live name, token, NFT, time or decryption results can annotate the
 device-decoded operand but have no representation capable of replacing it.
+The token role of a token-amount formatter is optional. When absent, firmware
+must display the device-decoded integer as an unknown-token value; token
+threshold, chain and native-alias roles are then forbidden.
 
 ### 7. Display instruction table