diff --git a/docs/use-psa-crypto.md b/docs/use-psa-crypto.md
new file mode 100644
index 0000000..a4f43b7
--- /dev/null
+++ b/docs/use-psa-crypto.md
@@ -0,0 +1,19 @@
+This document describes the compile-time configutation option
+`MBEDTLS_USE_PSA_CRYPTO`: its current effects as well as some design
+considerations and plans for the future.
+
+Current effects
+===============
+
+(To be written.)
+
+Parts that are not affected yet
+===============================
+
+(To be written.)
+
+Design considerations
+=====================
+
+(To be written.)
+
diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index 2c7bed2..cc80471 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -2119,6 +2119,9 @@
  * will still continue to work as usual, so enabling this option should not
  * break backwards compatibility.
  *
+ * \note See docs/use-psa-crypto.md for a complete description of what this
+ * option currently does, and of parts that are not affected by it so far.
+ *
  * \warning The PSA Crypto API is in beta stage. While you're welcome to
  * experiment using it, incompatible API changes are still possible, and some
  * parts may not have reached the same quality as the rest of Mbed TLS yet.