diff --git a/README.md b/README.md
index edf51c2a7640ea670ebbe84a4be8d871f6366e66..49bda35b85b6740f28a15db84ecdffaeabe36aac 100644
--- a/README.md
+++ b/README.md
@@ -5,3 +5,31 @@ Removes redundant files from a karaoke collection.
 A collection may include multiple versions of the same song, from multiple
 karaoke studios/labels. This script finds such songs, and moves the less-desired
 copies into a different directory.
+
+There's nothing fancy here, just looking at filenames and choosing the ones we want.
+
+## Usage
+
+Probably don't. This was a one-off script and it's probably not very useful to
+anyone else, except as an example of a quick and dirty way to sort a bunch of files.
+
+## Example filenames
+
+### Before
+
+* `Karaoke/ArtistA - TrackX [Label1].mp3`
+* `Karaoke/ArtistA - TrackX [LabelF].mp3`
+* `Karaoke/ArtistA - TrackX [Label#@!].mp3`
+* `Karaoke/ArtistA - TrackX [LabelBest].mp3`
+* `Karaoke/ArtistA - TrackX [Label2].mp3`
+
+### After
+
+Assuming we configure `LabelBest` above the others...
+
+* `Karaoke/ArtistA - TrackX [LabelBest].mp3`
+
+* `Other/ArtistA - TrackX [Label1].mp3`
+* `Other/ArtistA - TrackX [LabelF].mp3`
+* `Other/ArtistA - TrackX [Label#@!].mp3`
+* `Other/ArtistA - TrackX [Label2].mp3`
diff --git a/karaokeclean.py b/karaokeclean.py
index d77f682a4debeb4f32d8ffd2bf864e3541a98a6e..c45d51e83e8a700d34d21b59581b4225a468111c 100644
--- a/karaokeclean.py
+++ b/karaokeclean.py
@@ -12,6 +12,8 @@ EXTRA_DIR = "/media/anton/Karaoke/Karaoke_Extra"
 
 FILENAME_REGEX = re.compile(r"(?P<song>.*)\[(?P<label>.*)\](?P<ext>.*)")
 
+
+# List of karaoke labels in order of preference.
 PREFERENCES = [
     "Karaoke",
     "SC Karaoke",