Test, validate and match regular expressions
Matches markdown link fragments of the form 'SAIL_Recipes.md#section' immediately before a closing parenthesis, as found in links like [text](SAIL_Recipes.md#anchor). It captures the filename, the hash separator, and the anchor/heading reference separately, running case-insensitively across all occurrences. Typically used in documentation maintenance scripts to repair or rewrite in-page anchor links pointing to the SAIL Recipes file.