diff --git a/ldap/compositetypes/composite_types.go b/ldap/compositetypes/composite_types.go
index 32a1978c066daad0bf8edc452e61f73f8ac5d818..6df7b00677368e8dcde27888f30e6094d757026e 100644
--- a/ldap/compositetypes/composite_types.go
+++ b/ldap/compositetypes/composite_types.go
@@ -103,7 +103,8 @@ func UnmarshalEncryptedKey(s string) (*EncryptedKey, error) {
 //
 // The serialized format follows part of the U2F standard and just
 // stores 64 bytes of the public key immediately followed by the key
-// handle data, with no encoding.
+// handle data, with no encoding. Note that the public key itself is a
+// serialization of the elliptic curve parameters.
 //
 // The data in U2FRegistration is still encoded, but it can be turned
 // into a usable form (github.com/tstranex/u2f.Registration) later.