Regex Editor & Tester

This regex matches usernames that start and end with an alphanumeric character, containing only letters, numbers, underscores, hyphens, or dots. It enforces strict formatting rules by preventing consecutive or trailing separators, requiring an alphanumeric character after every optional underscore, hyphen, or period. It is specifically tailored for validating eBay usernames or similar platform-specific user identifiers across multiple lines of input.