Document URL:
https://access.redhat.com/documentation/en-us/red_hat_update_infrastructure/3.0/html/system_administrators_guide/registration_and_subscriptions#download_entitlement_certificate

Section Number and Name:
4.6. Download an Entitlement Certificate

Describe the issue:
The instruction to download RHUI entitlement certificate presupposes
that RHUA is already registered to the RH customer portal site w/ using subscription-manager.

However, there is a case that the cert needs to be gotten before setup RHUA
server and make it registered to the customer portal site.

Suggestions for improvement:
Add a section to show the steps like the follwoings to get the cert.

1. Log in to the Customer Portal
2. Click on My Subscriptions.
3. Click on the Systems tab in the Red Hat Subscription Management page.
4. Click [new] button to create a RHUI system profile
5. Create a RHUI system profile:

   - System Type: Select "Red Hat Update Infrastructure"
   - Name: Enter the name or something of RHUA to be made later
   - Version: Select "2.1.3 and above"

6. Click [Subscriptions] of the created profile page
7. Click [Attach Subscriptions] to attach CCSP subs to the RHUA
8. ...
9. Click [Download Certificate] to download the cert

Additional information:
AFAIK, most customers have only single CCSP RHUI subscription and
cannot register more than one RHUAs to the customer portal site.