• "properties" is not marked as required, even though it MUST be specified on a PUT
  

  azure-rest-api-specs/specification/network/resource-manager/Microsoft.Network/stable/2021-02-01/virtualNetwork.json

  Lines 1851 to 1855 in 88e7838

  	"properties": {
  	"x-ms-client-flatten": true,
  	"$ref": "#/definitions/VirtualNetworkPropertiesFormat",
  	"description": "Properties of the virtual network."
  	},

• "location" is not marked as required, even though it's required on a PUT:
  

  azure-rest-api-specs/specification/network/resource-manager/Microsoft.Network/stable/2021-02-01/network.json

  Lines 156 to 159 in 88e7838

  	"location": {
  	"type": "string",
  	"description": "Resource location."
  	},

I suspect this also applies to different Microsoft.Network resources, different properties, and different API versions.

First raised here: Azure/bicep#784 (comment)