x-ms-parameter-location
`x-ms-parameter-location` appears on parameter objects. Its value is a string. Used by 9 providers across 536 OpenAPI documents. It sits in the `x-ms-` namespace, so its meaning is defined by ms tooling rather than by OpenAPI. Observed values include `method`, `client`. Consistent with data & schema semantics — this is inferred from where the key appears and what it carries, not from any published definition.
Where it appears
| Location in the document | Occurrences | |
|---|---|---|
| other | 3 | |
| parameter | 2949 | |
| server | 1 | |
| operation | 28 | |
| path | 40 | |
| schema | 2 |
What its value looks like
| Value shape | Occurrences |
|---|---|
| string | 3023 |
Observed values
Sampled from the specifications, most frequent first.
Providers publishing it
All 9.
Why this is not in OpenAPI
Extensions exist because a provider needed something the specification would not carry. Most of what they hold is not the API contract at all — it is operational metadata about the contract: documentation, lifecycle, policy, provenance, and now agents. That metadata is usually better placed alongside the contract, in an Overlay or an APIs.json index, than crammed inside it. See everything else doing the data & schema semantics job.