Explanation of :

 Frontend(?:(?<!Called).)*

• Frontend matches the characters Frontend literally (case sensitive)
• Non-capturing group (?:(?<!Called).)*
  • (....)* :Quantifier — Matches between zero and unlimited times, as many times as possible, giving back as needed (greedy)
  • Negative Lookbehind (?<!Called)
  • Assert that the Regex below does not match
  • <Called >matches the characters Called literally (case sensitive)
  • . matches any character (except for line terminators)