HowTo, with steps that actually work
A genuinely useful procedure: checking what structured data a page really ships, rather than what it claims to.
Unlike most of the collection, the subject of this specimen is real and the steps below work. That is deliberate: HowTo is a type where a hollow example proves nothing.
Check what a page actually ships
Plenty of pages describe their structured data in a blog post, a plugin settings screen or a tab in the CMS. None of that is evidence. The only thing that counts is what arrives in the response a crawler receives, and it takes about a minute to check.
Step 1. Fetch the raw response, not the rendered page
View the page source rather than the inspector. The inspector shows the DOM after JavaScript has run; the raw response is what a parser gets first. If the markup is only in the DOM, say so out loud, because that is a different situation with different consequences.
Step 2. Find every ld+json block
Search the source for application/ld+json. Count the blocks. More than one is normal and fine. Zero, on a page whose CMS claims to be emitting schema, is the finding.
Step 3. Parse each block on its own
Paste each block into a JSON parser. A block that does not parse ships nothing useful no matter how good it looks, and this is where most real-world breakage lives: a trailing comma, a smart quote pasted in from a document, an unescaped line break inside a description.
Step 4. Compare it against the page
Read the values against what the page actually says. Prices that no longer match, opening hours from a previous season, a rating that appears nowhere on the page. Markup drifts away from content quietly, because nothing on the page breaks when it does.
Step 5. Check what is being asserted about other people
Ratings, review counts and review bodies are claims about what other people thought. Ask where each one came from. If nobody can point to the source, the honest fix is to remove the property, not to soften the number.