diff --git a/whatwg.org/style-guide b/whatwg.org/style-guide
index a89ac9464..f1a0ea2ff 100644
--- a/whatwg.org/style-guide
+++ b/whatwg.org/style-guide
@@ -66,6 +66,7 @@
Use the Oxford Comma.
Avoid "one of" unless it's followed by a bulleted list. You can normally leave it out and just use "or". If you cannot leave it out, that might be a good indication you want to use a bulleted list for clarity.
"A hierarchy" (not "an").
+ Use e.g., and i.e., instead of their non-comma-ending variants.
Casing