Username Rules for Unicode & Homoglyph Attacks
Usernames using lookalike characters from different alphabets to impersonate legitimate accounts.
Why These Usernames Are Reserved
The Cyrillic "а" looks identical to the Latin "a" but is a different Unicode character. Attackers register "аdmin" (Cyrillic a) when "admin" is blocked. This is called a homoglyph attack. Platforms need to normalize usernames and block visually similar alternatives to prevent this entire class of impersonation.
Common Examples
API Enforcement
Check usernames in this category programmatically:
Related Pages
Username Rules
Browse all rule categories
Reserved Usernames
Overview of reserved usernames
Username Rules for Security & Authentication
Security-related terms like login, password, and verify that could be exploited for phishing and credential theft.
Username Rules for Brand Names & Trademarks
Trademarked company names and brand identifiers that platforms protect to prevent impersonation and trademark infringement.