Production control note
Why flag duplicate guest display names?
Two attending guests with the same normalized display name can make finder lists and cards ambiguous; the desk flags the condition so the host can confirm identity and choose an appropriate guest-facing distinction.
Normalization is only a signal
Case and punctuation folding helps find likely collisions but cannot establish that two people are the same or different. Preserve the owner’s authoritative source outside the browser project and label every assumption that remains unverified.
Do not expose private qualifiers
Avoid solving ambiguity by printing sensitive party, relationship, service, or staff information. Review the result as production evidence, not as a recommendation or professional approval; the responsible people remain accountable for the decision.
Recheck after additions
A late addition can create a duplicate even when the original proof was clear. Carry this limitation into the proof and handoff so a fresh recipient knows what changed, what was checked, and what still requires human confirmation.