Merge branch 'main' into repo-sync

Author: Octomerger

data/reusables/pages/create-repo-name.md

@@ -1,2 +1,3 @@
-1. Type a name for your repository and an optional description. If you're creating a user or organization site, your repository must be named `<user>.github.io` or `<organization>.github.io`. For more information, see "[About {% data variables.product.prodname_pages %}](/articles/about-github-pages#types-of-github-pages-sites)."
+1. Type a name for your repository and an optional description. If you're creating a user or organization site, your repository must be named `<user>.github.io` or `<organization>.github.io`. If your user or organization name contains uppercase letters, you must lowercase the letters.
+For more information, see "[About {% data variables.product.prodname_pages %}](/articles/about-github-pages#types-of-github-pages-sites)."
    ![Create repository field](/assets/images/help/pages/create-repository-name-pages.png)