diff --git a/programs/ssl/ssl_client2.c b/programs/ssl/ssl_client2.c
index 6e047dc..0d7a418 100644
--- a/programs/ssl/ssl_client2.c
+++ b/programs/ssl/ssl_client2.c
@@ -127,9 +127,12 @@
 
 #if defined(POLARSSL_FS_IO)
 #define USAGE_IO \
-    "    ca_file=%%s          default: \"\" (pre-loaded)\n" \
-    "    ca_path=%%s          default: \"\" (pre-loaded) (overrides ca_file)\n" \
-    "    crt_file=%%s         default: \"\" (pre-loaded)\n" \
+    "    ca_file=%%s          The single file containing the top-level CA(s) you fully trust\n" \
+    "                        default: \"\" (pre-loaded)\n" \
+    "    ca_path=%%s          The path containing the top-level CA(s) you fully trust\n" \
+    "                        default: \"\" (pre-loaded) (overrides ca_file)\n" \
+    "    crt_file=%%s         Your own cert and chain (in bottom to top order, top may be omitted)\n" \
+    "                        default: \"\" (pre-loaded)\n" \
     "    key_file=%%s         default: \"\" (pre-loaded)\n"
 #else
 #define USAGE_IO \
diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c
index f6cf487..cc94e5c 100644
--- a/programs/ssl/ssl_server2.c
+++ b/programs/ssl/ssl_server2.c
@@ -184,9 +184,12 @@
 
 #if defined(POLARSSL_FS_IO)
 #define USAGE_IO \
-    "    ca_file=%%s          default: \"\" (pre-loaded)\n" \
-    "    ca_path=%%s          default: \"\" (pre-loaded) (overrides ca_file)\n" \
-    "    crt_file=%%s         default: \"\" (pre-loaded)\n" \
+    "    ca_file=%%s          The single file containing the top-level CA(s) you fully trust\n" \
+    "                        default: \"\" (pre-loaded)\n" \
+    "    ca_path=%%s          The path containing the top-level CA(s) you fully trust\n" \
+    "                        default: \"\" (pre-loaded) (overrides ca_file)\n" \
+    "    crt_file=%%s         Your own cert and chain (in bottom to top order, top may be omitted)\n" \
+    "                        default: \"\" (pre-loaded)\n" \
     "    key_file=%%s         default: \"\" (pre-loaded)\n"
 #else
 #define USAGE_IO \