diff --git a/Readme.markdown b/Readme.markdown
index 8244fbe..8346290 100644
--- a/Readme.markdown
+++ b/Readme.markdown
@@ -22,6 +22,8 @@ ioreg -l | awk -F\" '/board-id/ { print $4 }'
 
 Download the AHT for your computer model and use the contents to restore the `/System/Library/CoreServices/.diagnostics` folder, then reboot while holding `d` to start the diagnostic tools.
 
+Note that there is no one-to-one correspondence between hardware model and AHT. For some models no hardware test could be found, while others seem to have multiple AHT. As the differences are not clear, feel free to try them out, to see which one works best for your hardware.
+
 
  Download Links
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