updating a broken example and clarifying documentation

Author: shaselton-usds

examples/in-network-rates/in-network-rates-no-npi.json

@@ -18,7 +18,7 @@
           "npi": [1111111111],
           "tin": {
             "type": "npi",
-            "value": "0"
+            "value": "1234567890"
           }
         }
       ]

schemas/in-network-rates/README.md

@@ -69,7 +69,9 @@ This type defines a negotiated rate object.
 
 For most businesses reporting cases, a tax identification number (tin) is used to represent a business. There are situations where a provider's social security number is still used as a tin. In order to keep private personally identifiable information out of these files, substitute the provider's npi number for the social security number. When a npi number is used, it is assumed that the provider would otherwise be reporting by their social security number.
 
-In contractual arrangements that are only made at the TIN level, where NPIs are unknown or otherwise unavailable, the value "0" should be reported for the NPI field. In contractual arrangements where both the NPI and TIN are available, both are required to be disclosed.
+**Important:** The `tin.value` field must contain a valid 10-digit NPI (starting with 1-9) when `tin.type` is "npi", or a valid EIN format when `tin.type` is "ein". The value "0" is NOT a valid `tin.value`.
+
+In contractual arrangements that are only made at the TIN level, where NPIs are unknown or otherwise unavailable, the value `0` should be reported in the **`npi` array field** (e.g., `"npi": [0]`), NOT in the `tin.value` field. In contractual arrangements where both the NPI and TIN are available, both are required to be disclosed.
 #### Provider Reference Object
 
 This type defines a provider reference object. This object is used in the `provider_references` array found on the root object of the in-network schema. The Provider Group Id is a unique interger ID that is defined by the user to be referenced in the [Negotiated Rate Details Object](#negotiated-rate-details-object) in the `provider_references` array. An example of using provider references can be found in the definition of [provider reference objects](https://github.com/CMSgov/price-transparency-guide/blob/c3ba257f41f4b289b574557e2fcf0833c36ef79f/examples/in-network-rates/in-network-rates-fee-for-service-single-plan-sample.json#L10-L28) and then the usages of the `provider_group_id`s in the [negotiated rate object](https://github.com/CMSgov/price-transparency-guide/blob/c3ba257f41f4b289b574557e2fcf0833c36ef79f/examples/in-network-rates/in-network-rates-fee-for-service-single-plan-sample.json#L86).