Exercise 3: A Custom Taxonomy With hierarchical => false — Possible Solution ==================================================================== WHAT THIS SETTING MEANS, PER THIS CHAPTER'S OWN TABLE ------------------------------ Per this chapter's own comparison table, hierarchical set to false "behaves like: Tags, per WordPress Fundamentals 7 - flat, no hierarchy." A "skill_level" taxonomy registered with hierarchical => false will therefore behave exactly like Tags do, rather than like Categories. WHAT THIS MEANS CONCRETELY, USING WORDPRESS FUNDAMENTALS 7's OWN DEFINITIONS ------------------------------ Per WordPress Fundamentals 7's own Categories-vs-Tags material (directly referenced by this chapter), a flat, Tag-like taxonomy has no parent/child structure at all - every skill_level term (for example, "Beginner," "Intermediate," "Advanced") would sit at the same level, with no ability to nest one term underneath another. It would also be entirely optional to assign, following the same "entirely optional" trait Tags have per that earlier chapter, rather than requiring at least one term the way Categories default to "Uncategorized" if none is chosen. WHY THIS FOLLOWS DIRECTLY FROM THIS CHAPTER'S OWN "NEVER SPECIAL" REVEAL ------------------------------ Per this chapter's own finding-box, "'Category' and 'Tag' are simply the names of two taxonomies WordPress core happens to register automatically, using exactly this same register_taxonomy() mechanism. Setting hierarchical to true or false on a custom taxonomy is, mechanically, the same choice that separates Categories from Tags in the first place." Since hierarchical is the exact underlying setting that makes Categories hierarchical and Tags flat, setting it to false on "skill_level" produces a taxonomy that is, mechanically, built the same way Tags are - not merely similar to Tags by coincidence, but using the identical configuration choice. WHY THIS ISN'T "SIMILAR TO A TAG" BUT GENUINELY THE SAME MECHANISM ------------------------------ The distinction matters: "skill_level" isn't approximating tag-like behavior through some separate feature - it IS built from the exact same underlying taxonomy system, with the same single setting flipped the same way Tags' own registration flips it. There's no meaningful difference in kind between a flat custom taxonomy and the built-in Tags taxonomy, only a difference in which specific taxonomy is being configured. WHY THIS WORKS AS AN ANSWER ------------------------------ It applies this chapter's own comparison table directly to the specific taxonomy named in the question, explains concretely what flat/non-hierarchical behavior means using WordPress Fundamentals 7's own Categories-vs-Tags definitions, and reinforces why this is a genuine mechanical equivalence rather than a loose similarity.