x-default represents a neutral destination or an explicit default variant.

Expectations and evidence

Required inputs (protocol identifiers)

hreflang, http, intent

When it applies

Clusters where x-default is declared or required by policy.

How to check

Check its presence and role in every relevant multilingual cluster.

Expectation

The destination is accessible and matches the selection flow or the deliberate default variant.

Evidence to retain

Documented, accessible x-default URL consistent with the journey.

Non-applicability

No x-default required or declared; retain the policy justification.

Limitations

x-default is not mandatory in every case.

Outcome clarification

C requires all expectations across the declared scope. NC requires evidenced contradiction; otherwise NT. NA requires evidence of non-applicability.

Reference scope

Technical reference; the TSEP acceptance rule remains an editorial proposal.