diff --git a/chacha.h b/chacha.h
index b1099a35..a126b563 100644
--- a/chacha.h
+++ b/chacha.h
@@ -5,6 +5,10 @@
//! \file chacha.h
//! \brief Classes for ChaCha8, ChaCha12 and ChaCha20 stream ciphers
+//! \details Crypto++ provides Bernstein and ECRYPT's ChaCha from ChaCha,
+//! a variant of Salsa20 (2008.01.28). Bernstein's implementation is _slightly_ different from the TLS working group's
+//! implementation for cipher suites TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256,
+//! TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256, and TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256.
//! \since Crypto++ 5.6.4
#ifndef CRYPTOPP_CHACHA_H
@@ -58,6 +62,9 @@ struct ChaCha8 : public ChaCha_Info<8>, public SymmetricCipherDocumentation
//! \class ChaCha12
//! \brief ChaCha12 stream cipher
+//! \details Bernstein and ECRYPT's ChaCha is _slightly_ different from the TLS working group's implementation for
+//! cipher suites TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256,
+//! TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256, and TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256.
//! \sa ChaCha, a variant of Salsa20 (2008.01.28).
//! \since Crypto++ 5.6.4
struct ChaCha12 : public ChaCha_Info<12>, public SymmetricCipherDocumentation
@@ -69,6 +76,9 @@ struct ChaCha12 : public ChaCha_Info<12>, public SymmetricCipherDocumentation
//! \class ChaCha20
//! \brief ChaCha20 stream cipher
//! \sa ChaCha, a variant of Salsa20 (2008.01.28).
+//! \details Bernstein and ECRYPT's ChaCha is _slightly_ different from the TLS working group's implementation for
+//! cipher suites TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256,
+//! TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256, and TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256.
//! \since Crypto++ 5.6.4
struct ChaCha20 : public ChaCha_Info<20>, public SymmetricCipherDocumentation
{