Write a filter to find all tiddlers that do not link to a tiddler that has a tag which is both red and begins with the letter C, sorted by title in reverse alphabetical order.

Consider a “red” tag to be one that has a value of #ff0000 in its color field. We'll talk more about tag colors in Classifying Tags; for now, you can test by editing the tiddlers of one or two tags to have such a color field value.

English is terrible at expressing complicated conditions like this, so to be sure you read it right, here's the sentence decomposed hierarchically and written more precisely:

• All tiddlers matching these criteria:
  • The tiddler does not link to:
    • Another tiddler:
      • That has a tag:
        • Which is red (color field's value is #ff0000)
        • The name of which begins with a capital letter C
• Sorted by title in reverse alphabetical order.

Tip 1: The prefix operator returns items from its input whose title begins with a given string of text.

Tip 2: The is[] filter step will find all (non-shadow) tiddlers in the wiki.

A quick way to test your answer is to add a link from a tiddler that appears in the output to one of the tags you colored red; the tiddler should disappear from the list since it's now linking to a tiddler that has a red tag whose name begins with C.