Merge pull request #6487 from gilles-peskine-arm/legacy_or_psa-internal

diff --git a/include/mbedtls/constant_time.h b/include/mbedtls/constant_time.h
index c5de57a..fb1f7e9 100644
--- a/include/mbedtls/constant_time.h
+++ b/include/mbedtls/constant_time.h
@@ -1,6 +1,7 @@
 /**
  *  Constant-time functions
- *
+ */
+/*
  *  Copyright The Mbed TLS Contributors
  *  SPDX-License-Identifier: Apache-2.0
  *
diff --git a/include/mbedtls/legacy_or_psa.h b/include/mbedtls/legacy_or_psa.h
index 2156be9..f872dda 100644
--- a/include/mbedtls/legacy_or_psa.h
+++ b/include/mbedtls/legacy_or_psa.h
@@ -1,7 +1,10 @@
 /**
  *  Macros to express dependencies for code and tests that may use either the
- *  legacy API or PSA in various builds; mostly for internal use.
- *
+ *  legacy API or PSA in various builds. This whole header file is currently
+ *  for internal use only and both the header file and the macros it defines
+ *  may change or be removed without notice.
+ */
+/*
  *  Copyright The Mbed TLS Contributors
  *  SPDX-License-Identifier: Apache-2.0
  *