Am not getting the domainNameLabel correct

Hope it's okay to post a general question here that is not really an issue, but more my lack of understanding on what is being expected. I'm following this post on the Dell site (https://community.emc.com/docs/DOC-80070) to prepare and run this template. The writer said that the value for the Domain Name Label parameter in the setup script must be used as the CN in the SSL certificate that is created. In his example he has this value as "CN=cseregistry.rack04.cloudapp.azs.mhclabs.com". So in my setup script (and in my certificate) I used the value of "csregistry.local.cloudapp.azurestack.external", as this seemed comparable for my Azure Stack SDK environment. But when I run the deploy script, the deployment fails, complaining that "The domain name label csregistry.local.cloudapp.azurestack.external is invalid. It must conform to the following regular expression:
^[a-z][a-z0-9-]{1,61}[a-z0-9]$." Obviously I am misunderstanding something. Can anyone set me straight on this?

レポートで参照されているセットアップスクリプトとデプロイスクリプトから始め、それらの Domain Name Label の処理をリンク先の Dell のガイダンスと比較します。パラメーターにどの値が期待されるか、またそれが SSL 証明書の CN とどのように関係するかを文書化します。deployment 要件が明確になった時点で issue は完了です。

索引モデルが issue の本文から書いたものです。