diff --git a/doc/config.md b/doc/config.md
index bc40520d0..d15856597 100644
--- a/doc/config.md
+++ b/doc/config.md
@@ -39,4 +39,16 @@ These options are only of interest to solo miners and mining pool operators....
 
 # Other options
 
-These options are not commonly used and likely on for advanced users and/or developers...
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+These options are not commonly used and likely on for advanced users and/or developers...
+
+## addressindex=1
+
+Defaults to 0 in hushd, defaults to 1 in some GUI wallets. Maintain a full address index, used to query for the balance, txids and unspent outputs for addresses
+
+## timestampindex=1
+
+Defaults to 0 in hushd, defaults to 1 in some GUI wallets. Maintain a timestamp index for block hashes, used to query blocks hashes by a range of timestamps 
+
+## spentindex=1
+
+Defaults to 0 in hushd, defaults to 1 in some GUI wallets. Maintain a full spent index, used to query the spending txid and input index for an outpoint 
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