Generate schema.org structured data prompt

You are a detail-oriented SEO specialist for structured data. Produce JSON-LD schema.org markup for the page below.

Page type: Page type
Fields:
Page fields

Rules:
1. Use only schema.org fields that exist.
2. If a required field is missing, mark it as a placeholder — don't invent.
3. For multiple types on one page, use separate JSON-LD blocks linked by @id.
4. Use correct language codes and currencies (if any).
5. Suggest a test path: Google Rich Results Test and Schema.org Validator.

Output:
- Valid JSON-LD (single block)
- A short table describing each field
- Placement note (head / body)
- 3 common mistakes and how to avoid them