diff --git a/README.md b/README.md
index 6751f11..3e2ad7f 100644
--- a/README.md
+++ b/README.md
@@ -9,6 +9,12 @@ used.
 The result (not much updated, though) can be found
 [here](https://tobast.fr/files/trumprank.txt).
 
+## Methodology
+
+A word is considered to be a contiguous sequence of letters and quotes (`'`)
+only. Words that have less than four occurrences are removed (considered
+irrelevant — probably some random name).
+
 ## Install
 
 Clone this reopsitory with submodules: `git clone --recurse-submodules`