Clarify which TLDs can be issued wildcard certificates

[CBonnell]

In the validation-sc teleconference on 2025-08-07, there was some uncertainty expressed about which TLDs can have a wildcard certificate issued.

Some TLDs that were discussed:

• .com
• .sb
• .toyota, .apple

The Base Domain Name definition explicitly references ICANN specification 13, which may restrict the set of gTLDs allowed.

A more comprehensive review of the language in the various sections of BR is needed to determine the current rules and determine whether the current rules are desirable.

[github-actions]

This issue was created based on:

• TLS BR Version 2.1.6
• EVG Version 2.0.1

[CBonnell]

This issue is related to #229, as both deal with wildcard issuance for TLDs.

[richardwsmith]

As with ADN, a definition should not contain normative requirements, so if the definition of Base Domain Name alters the plain meaning of requirement text in the body of the document in a way that is not plain and clear from the requirement text itself, the definition should be simplified and the normative requirement in the body of the document should be clarified to stated exactly what is or is not allowed.