I'm creating an extremely difficult challenge requiring the use of advanced regex techniques such as mixed formats (emails, phone numbers, dates with different separators), complex escapes for special characters, and patterns with backreferences or negative lookaheads. The text sample includes six challenging target items: an email with underscores and subdomains, a hyphenated phone number, a date with time following a specific format, a secret code resembling a pattern that may require backrefe... (truncated)