Build, test, and debug regular expressions
Validates a single first or last name per line: one or more Unicode letters (\p{L}), optionally followed by exactly one hyphen or apostrophe and more letters, matching names like María, O'Brien, or Anne-Marie. Anchored with ^ and $ in multiline mode, so each line must contain only the name—no spaces, digits, or repeated separators. Commonly used for user registration and contact form validation across languages.