Public regex example: anonymize without changing structure

A useful public regex question shows the exact pattern, flags, expected match, actual match, and a minimal sample string. Replace real addresses, identifiers, and private text with synthetic values that retain the same punctuation, Unicode, or line breaks causing the issue. Include one expected non-match so readers understand the boundary. Avoid posting a giant production log; it may expose data and obscure the problem. If performance is the issue, state the approximate input length and repetition pattern.