diff --git a/Commands.md b/Commands.md
index f0ce0bf..2361b69 100644
--- a/Commands.md
+++ b/Commands.md
@@ -12,13 +12,32 @@ The "#" denotes that this is dependent upon the command.
 | 0x1# | Read data  |
 | 0x2# | Write data |
 
+## Parameters
+### Configuration
+| hex | config option | description | accepted values |
+| :- | :- | :- | :- |
+| TBD | TBD | TBD | TBD |
+
+### Voltage source
+| hex | source |
+| :- | :- |
+| 0x01 | Internal |
+| 0x02 | External |
+| 0x03 | Thermistor |
+
+### Fan
+| hex | fan |
+| :- | :- |
+| 0x01 | Fan 1 |
+| 0x02 | Fan 2 |
+
 ## Complete command table
 | command | description | parameter |
 | :-- | :-- | :-- |
-| 0x11 | Read config | Config option, see config page for values |
+| 0x11 | Read config | Config option |
 | 0x12 | Read  voltage | Voltage source |
 | 0x13 | Read temperature | |
 | 0x14 | Read current fan speed | fan number |
 | 0x15 | Read bulk fan speed | fan number |
-| 0x21 | Write config | Config option, see config page for values |
+| 0x21 | Write config | Config option |
 | 0x22 | Clear stored fan speed data | fan number |
\ No newline at end of file