Investigate and improve the style-guide checks to reduce false positives

In reference to #94, #427.
Improved regex or testing approach for checks which are generating too many false positives.
**Any PR for this issue should use the tag ``Addresses`` instead of ``closes``.**

Start by reading the issue's references, #94 and #427, then locate the style-guide checks responsible for the reported false positives. Review their regexes and current testing approach; done means the checks produce fewer false positives and the changed behavior is covered by tests.

Written by the indexing model from the issue text.