Thanks for the answer - I was completely unaware that there was a difference. To my way of thinking a sub-category should be listed only under the appropriate heading, and there should be no link in another category. I'm sure I'm not the first person to play a group of quizzes only to find they don't count.
The links are there to encourage people to find more quizzes on a similar topic they're already looking into. Someone playing quizzes about Disney, for instance, can then be linked to Disney Movies, Disney video games, or Walt Disney himself, all from one spot depending on what they fancy in that moment.
The main page for any quiz should list the specific category (it's under the introduction on the opening page of a quiz). For instance, one in 'The Amazing Race' section would say
Category: Fun Trivia: Quizzes: Television: Television A-C: Amazing Race, The
The third field will always be the specific category.