Underscore not allowed either
diff --git a/README.md b/README.md
index 5e79b85..4769428 100644
--- a/README.md
+++ b/README.md
@@ -35,8 +35,6 @@
The website is built with [Pelican](https://blog.getpelican.com).
-You can use the [infrastructure-pelican Dockerfile](https://github.com/apache/infrastructure-pelican/blob/master/Dockerfile) build the website locally for testing.
-
Continuous Integration / Continuous Deployment (CI/CD) is via the [.asf.yaml file](https://cwiki.apache.org/confluence/display/INFRA/Git+-+.asf.yaml+features)
mechanism, which runs [Buildbot](https://ci2.apache.org/#/builders/3/).
@@ -91,3 +89,4 @@
Note: the branch name must not include any "." characters,
or browsers will refuse to display the site due to an invalid SSL certificate.
+The underscore character should not be used either, as it is disallowed in host names.
