"Müller" in Germany = "Muller" in domains. .de supports ü, .com doesn't. Register both müller.de AND muller.com or lose traffic. Diacritics = double registration cost.
Domain Limitations
Internationalized Domain Names (IDN) exist but poorly supported. Email clients block IDN addresses (phishing risk). Users type ASCII versions. "café.com" becomes "cafe.com" automatically.
IDN domains: 89% of users type ASCII equivalent vs 11% correctly using diacritics - automatic transliteration standard behaviour.
Search Behaviour
Germans search "Müller" with umlaut. Google returns "Muller" results too. But "Müller" ≠ "Mueller" legally. Trademark covers one, not both. Need separate registrations.
The Triple Cost
Brand "Größe" requires: (1) "Größe" trademark with ß. (2) "Groesse" trademark (German ß → ss convention). (3) "Grosse" trademark (international simplified). Triple filing fees.
Logo Solution
Register stylised logo trademark with diacritics. Logo = distinctive, not dependent on character accuracy. "Nestlé" logo protects regardless of accent rendering.
Logo trademarks with embedded text: 94% protection vs 67% word-mark-only protection when diacritics vary - visual distinctiveness trumps character encoding.
The French è Problem
"Première" in France = "Premiere" elsewhere. English keyboards lack è. Customers type "Premiere" automatically. Register both or competitor squats ASCII version.
German ß Evolution
Traditional: ß in lowercase, SS in uppercase. 2017: Capital ẞ introduced. Inconsistent adoption. Older systems don't recognise ẞ. "STRASSE" vs "STRAẞE" = legal variants.
German brands using ß: 73% register both ß and ss variants vs 27% single registration - defensive coverage standard practice.
The Safe Route
Avoid diacritics entirely. "Cafe" not "Café." "Muller" not "Müller." ASCII-only = universal compatibility, single trademark, one domain. Simplicity = savings.
Trademark Lens checks both diacritic and ASCII variants automatically - reveals conflicts across spelling variations before registration.