diff --git a/.env.sample b/.env.sample
index de93ed0..2b4d548 100644
--- a/.env.sample
+++ b/.env.sample
@@ -10,6 +10,9 @@ MEDIAWIKI_SITENAMESPACE="Example_Wiki"
 MEDIAWIKI_EMAIL_CONTACT="info@wiki.example.com"
 MEDIAWIKI_EMAIL_FROM="wiki@wiki.example.com"
 MEDIAWIKI_LOGO_FILE='$wgResourceBasePath/resources/assets/wiki.png'
+
+# list of language options (without ".json"):
+# https://gerrit.wikimedia.org/g/mediawiki/core/%2B/HEAD/languages/i18n
 MEDIAWIKI_LANGUAGE="en"
 
 MEDIAWIKI_IS_PRIVATE=1