diff --git a/include/mbedtls/x509_crt.h b/include/mbedtls/x509_crt.h
index ff1422b..c172857 100644
--- a/include/mbedtls/x509_crt.h
+++ b/include/mbedtls/x509_crt.h
@@ -656,6 +656,10 @@
  *                  ::mbedtls_x509_crt_frame on the stack and call this function
  *                  on it, in which case no allocation/freeing has to be done.
  *
+ * \note            You may also use mbedtls_x509_crt_frame_acquire() and
+ *                  mbedtls_x509_crt_frame_release() for copy-less variants
+ *                  of this function.
+ *
  * \return          \c 0 on success. In this case, \p dst is updated
  *                  to hold the frame for the given CRT.
  * \return          A negative error code on failure.
@@ -670,6 +674,10 @@
  * \param pk        The address of the destination PK context to fill.
  *                  This must be initialized via mbedtls_pk_init().
  *
+ * \note            You may also use mbedtls_x509_crt_pk_acquire() and
+ *                  mbedtls_x509_crt_pk_release() for copy-less variants
+ *                  of this function.
+ *
  * \return          \c 0 on success. In this case, the user takes ownership
  *                  of the destination PK context, and is responsible for
  *                  calling mbedtls_pk_free() on it once it's no longer needed.