[KevinH]

The Classes in HTML report is different. It looks ONLY for class entries (non-combinator) used in that xhtml file that exists in your css file with its own entry.

Since p.author itself does not exist as a separate entry in your Style0001.css it is not shown as existing in your css file since it technically does not exist on its own. In other words there is no selector p.author defined in your css file.

The only selector that encompasses p.author is in fact a descendent selector (a combinator) which is not a class selector (although it uses classes).

The CSS Selectors Report does in fact show that descendent selector is used and where.
And Delete Unused Selectors also properly detects its use.