# AIP013: missing-format-example
**Category:** Behavior
**Severity:** Info
When a prompt requests structured output (JSON, XML, YAML, CSV) or explicitly asks for "structured output" or "structured format", it should provide a concrete example or schema showing the desired shape.
## Triggers
- "return JSON", "output JSON", "respond with JSON", "produce JSON"
- Same patterns for XML, YAML, CSV
- "structured output" or "structured format"
## Example signals (to avoid the diagnostic)
- Contains `example:` (case-insensitive)
- Contains `for example`
- Contains a code fence (triple backticks)
- Contains a JSON object `{...}`
- Contains XML tag pairs `<...>`
## Example
**Bad:**
```
Please return JSON with the user's name and age.
```
**Good:**
```
Please return JSON with the user's name and age.
Example: {"name": "Alice", "age": 30}
```
## Rationale
Unexemplified format requests are easy for the model to misinterpret, resulting in malformed output, inconsistent field names, or unexpected nesting.