Updated API from documentation release

Author: ct-sdks[bot]

api-specs/api/types/category/CategoryDraft.raml

@@ -55,6 +55,8 @@ properties:
     type: string
     description: |
       User-defined unique identifier for the Category.
+
+      This field is optional for backwards compatibility reasons, but we strongly recommend setting it. Keys are mandatory for importing Categories with the [Import API](/../import-export/) and the [Merchant Center](/../merchant-center/import-data).
     pattern: ^[A-Za-z0-9_-]+$
     minLength: 2
     maxLength: 256

api-specs/api/types/customer/CustomerDraft.raml

@@ -8,6 +8,8 @@ properties:
     description: |
       User-defined unique identifier for the Customer.
       The `key` field is preferred over `customerNumber` as it is mutable and provides more flexibility.
+
+      This field is optional for backwards compatibility reasons, but we strongly recommend setting it. Keys are mandatory for importing Customers with the [Import API](/../import-export/).
     pattern: ^[A-Za-z0-9_-]+$
     minLength: 2
     maxLength: 256

api-specs/api/types/discount-code/DiscountCodeDraft.raml

@@ -7,6 +7,8 @@ properties:
     type: string
     description: |-
       User-defined unique identifier for the DiscountCode.
+
+      This field is optional for backwards compatibility reasons, but we strongly recommend setting it. Keys are mandatory for importing Discount Codes with the [Import API](/../import-export/) and the [Merchant Center](/../merchant-center/import-data).
     pattern: ^[A-Za-z0-9_-]+$
     minLength: 2
     maxLength: 256

api-specs/api/types/inventory/InventoryEntryDraft.raml

@@ -11,6 +11,8 @@ properties:
     type: string
     description: |
       User-defined unique identifier for the InventoryEntry.
+
+      This field is optional for backwards compatibility reasons, but we strongly recommend setting it. Keys are mandatory for importing InventoryEntries with the [Import API](/../import-export/) and the [Merchant Center](/../merchant-center/import-data).
     pattern: ^[A-Za-z0-9_-]+$
     minLength: 2
     maxLength: 256

api-specs/api/types/product/ProductDraft.raml

@@ -23,7 +23,9 @@ properties:
     description: |
       User-defined unique identifier for the Product.
 
-      To update a Product using the [Import API](/../import-export/product), the Product `key` must match the pattern `^[A-Za-z0-9_-]{2,256}$`.
+      This field is optional for backwards compatibility reasons, but we strongly recommend setting it. Keys are mandatory for importing Products with the [Import API](/../import-export/) and the [Merchant Center](/../merchant-center/import-data).
+
+      To update a Product using the Import API or Merchant Center, the Product `key` must match the pattern `^[A-Za-z0-9_-]{2,256}$`.
   description?:
     type: LocalizedString
     description: |

api-specs/api/types/product/updates/ProductSetKeyAction.raml

@@ -10,4 +10,4 @@ properties:
     description: |
       Value to set. If empty, any existing value will be removed.
 
-      To update a Product using the [Import API](/../import-export/product), the Product `key` must match the pattern `^[A-Za-z0-9_-]{2,256}$`.
+      To update a Product using the [Import API](/../import-export/) and the [Merchant Center](/../merchant-center/import-data), the Product `key` must match the pattern `^[A-Za-z0-9_-]{2,256}$`.