diff --git a/Discovery/DNS/README.md b/Discovery/DNS/README.md
index e7de9b3599..8222f5b2ad 100644
--- a/Discovery/DNS/README.md
+++ b/Discovery/DNS/README.md
@@ -4,3 +4,10 @@ This wordlist is a combination of the following wordlists with a few subdomains
 - bitquark-subdomains-top100000.txt
 - shubs-subdomains.txt
 - subdomains-top1million-110000.txt
+
+## `subdomains-top1million-*`
+
+> [!WARNING]
+> These wordlists are several years old, they were made in 2015. You will not be able to detect deployments of any services which were invented after 2015 using these wordlists, because their names will not be on the lists.
+
+These wordlists were [zone-transfered from Amazon's Alexa.com](https://gist.github.com/ethicalhack3r/6145925) in 2015. They are lists of the most used subdomains at the time, as reported by Alexa.com.
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