As this refers to each registry option as a method, it would make it extra clearer when reaching subsections 5.4 , 5.5 and 5.6 if the beginning/end of their titles included "Method a, b, or c" https://access.redhat.com/documentation/en-us/red_hat_openstack_platform/13/html/director_installation_and_usage/configuring-a-container-image-source#annotations:56960a4d-b5b5-4ab6-bc23-2f34c6ec897c
An example of this can be seen in the Advanced Overcloud Customization guide, sections 5.2 through 5.5, each of which are titled Example 1, Example 2 etc: https://access.redhat.com/documentation/en-us/red_hat_openstack_platform/13/html/advanced_overcloud_customization/sect-registering_the_overcloud#example_1_registering_to_the_customer_portal
*** This bug has been marked as a duplicate of bug 1657776 ***