Step 1
Filtering Out the Noise with Regex
Removing all tags that aren't "strong"
<(?!strong|\/strong)([^>]*)>
- Match the character "<" literally
- Assert that it is impossible to match the regex below starting at this position (negative lookahead)
- Match either the regular expression below (attempting the next alternative only if this one fails)
- Match the characters "strong" literally
- Or match regular expression number 2 below (the entire group fails if this one fails to match)
- Match the character "/" literally
- Match the characters "strong" literally
- Match the regular expression below and capture its match into backreference number 1
- Match any character that is NOT a ">"
- Between zero and unlimited times, as many times as possible, giving back as needed (greedy)
- Match the character ">" literally
