If you see the above BCP081 warning, it means you’re trying to use something like this, which is copied and pasted from Microsoft’s own reference page:

resource symbolicname 'Microsoft.ApiManagement/service/apis/schemas@2023-05-01-preview' = {

BCP081 means that the type Microsoft.ApiManagement/service/apis/schemas is not in the 2023-05-01-preview API version.

This Stack Overflow answer explains one way to find which API version the type is in, by searching Azure’s ARM GitHub repo.

So in my case, I went over to that repo, and then typed a / to search through the whole repo. I searched for Microsoft.ApiManagement/service/apis/schemas which returned these 5 results:

Which tells me that Microsoft.ApiManagement/service/apis/schemas is in 5 API versions:

• 2021-08-01
• 2022-08-01
• 2021-04-01-preview
• 2021-12-01-preview
• 2022-04-01-preview.

So I should change my bicep to use one of those versions to make the Warning go away:

resource symbolicname 'Microsoft.ApiManagement/service/apis/schemas@2022-08-01' = {

It seems to me that there’s a bug in Microsoft’s documentation generator in that it suggested I use 2023-05-01-preview, since using that version generates a warning.

As a side note, no matter which version of Microsoft.ApiManagement/service/apis/schemas I used, I couldn’t get it to deploy the Definition to APIM. The deployment would run without errors, but the Definition never appeared in the APIM portal. So I ended up using Microsoft.ApiManagement/service/schemas@2022-08-01 instead:

resource propertySchema 'Microsoft.ApiManagement/service/schemas@2022-08-01' = {
  name: 'property-definition'
  parent: apimService
  properties: {
    description: 'Used to validate /property request'
    document: loadJsonContent('apim/create-property-schema.json')
    schemaType: 'json'
    value: any(null)
  }
}

which deploys the schema to a different location, but is an acceptable workaround for my needs – the validate-content APIM policy.