Update doc

doc/manual-src/en/aria2c.rst

@@ -170,8 +170,11 @@ HTTP/FTP/SFTP Options
 
   If aria2 receives "file not found" status from the remote HTTP/FTP
   servers NUM times without getting a single byte, then force the
-  download to fail. Specify ``0`` to disable this option. This options is
-  effective only when using HTTP/FTP servers.
+  download to fail. Specify ``0`` to disable this option. This options
+  is effective only when using HTTP/FTP servers.  The number of retry
+  attempt is counted toward :option:`--max-tries`, so it should be
+  configured too.
+
   Default: ``0``
 
 .. option:: -m, --max-tries=<N>

src/usage_text.h

@@ -453,7 +453,9 @@
     "                              a single byte, then force the download to fail.\n" \
     "                              Specify 0 to disable this option.\n" \
     "                              This options is effective only when using\n" \
-    "                              HTTP/FTP servers.")
+    "                              HTTP/FTP servers. The number of retry attempt is\n" \
+    "                              counted toward --max-tries, so it should be\n" \
+    "                              configured too.")
 #define TEXT_URI_SELECTOR                                               \
   _(" --uri-selector=SELECTOR      Specify URI selection algorithm.\n"  \
     "                              If 'inorder' is given, URI is tried in the order\n" \