diff --git a/services/preview/apimanagement/mgmt/2018-01-01/apimanagement/productapi.go b/services/preview/apimanagement/mgmt/2018-01-01/apimanagement/productapi.go
index ac8974749153..1a773b7d4fd0 100644
--- a/services/preview/apimanagement/mgmt/2018-01-01/apimanagement/productapi.go
+++ b/services/preview/apimanagement/mgmt/2018-01-01/apimanagement/productapi.go
@@ -45,7 +45,8 @@ func NewProductAPIClientWithBaseURI(baseURI string, subscriptionID string) Produ
 // resourceGroupName - the name of the resource group.
 // serviceName - the name of the API Management service.
 // productID - product identifier. Must be unique in the current API Management service instance.
-// apiid - API identifier. Must be unique in the current API Management service instance.
+// apiid - API revision identifier. Must be unique in the current API Management service instance. Non-current
+// revision has ;rev=n as a suffix where n is the revision number.
 func (client ProductAPIClient) CheckEntityExists(ctx context.Context, resourceGroupName string, serviceName string, productID string, apiid string) (result autorest.Response, err error) {
 	if err := validation.Validate([]validation.Validation{
 		{TargetValue: serviceName,
@@ -57,9 +58,9 @@ func (client ProductAPIClient) CheckEntityExists(ctx context.Context, resourceGr
 				{Target: "productID", Name: validation.MinLength, Rule: 1, Chain: nil},
 				{Target: "productID", Name: validation.Pattern, Rule: `(^[\w]+$)|(^[\w][\w\-]+[\w]$)`, Chain: nil}}},
 		{TargetValue: apiid,
-			Constraints: []validation.Constraint{{Target: "apiid", Name: validation.MaxLength, Rule: 80, Chain: nil},
+			Constraints: []validation.Constraint{{Target: "apiid", Name: validation.MaxLength, Rule: 256, Chain: nil},
 				{Target: "apiid", Name: validation.MinLength, Rule: 1, Chain: nil},
-				{Target: "apiid", Name: validation.Pattern, Rule: `(^[\w]+$)|(^[\w][\w\-]+[\w]$)`, Chain: nil}}}}); err != nil {
+				{Target: "apiid", Name: validation.Pattern, Rule: `^[^*#&+:<>?]+$`, Chain: nil}}}}); err != nil {
 		return result, validation.NewError("apimanagement.ProductAPIClient", "CheckEntityExists", err.Error())
 	}
 
@@ -131,7 +132,8 @@ func (client ProductAPIClient) CheckEntityExistsResponder(resp *http.Response) (
 // resourceGroupName - the name of the resource group.
 // serviceName - the name of the API Management service.
 // productID - product identifier. Must be unique in the current API Management service instance.
-// apiid - API identifier. Must be unique in the current API Management service instance.
+// apiid - API revision identifier. Must be unique in the current API Management service instance. Non-current
+// revision has ;rev=n as a suffix where n is the revision number.
 func (client ProductAPIClient) CreateOrUpdate(ctx context.Context, resourceGroupName string, serviceName string, productID string, apiid string) (result APIContract, err error) {
 	if err := validation.Validate([]validation.Validation{
 		{TargetValue: serviceName,
@@ -143,9 +145,9 @@ func (client ProductAPIClient) CreateOrUpdate(ctx context.Context, resourceGroup
 				{Target: "productID", Name: validation.MinLength, Rule: 1, Chain: nil},
 				{Target: "productID", Name: validation.Pattern, Rule: `(^[\w]+$)|(^[\w][\w\-]+[\w]$)`, Chain: nil}}},
 		{TargetValue: apiid,
-			Constraints: []validation.Constraint{{Target: "apiid", Name: validation.MaxLength, Rule: 80, Chain: nil},
+			Constraints: []validation.Constraint{{Target: "apiid", Name: validation.MaxLength, Rule: 256, Chain: nil},
 				{Target: "apiid", Name: validation.MinLength, Rule: 1, Chain: nil},
-				{Target: "apiid", Name: validation.Pattern, Rule: `(^[\w]+$)|(^[\w][\w\-]+[\w]$)`, Chain: nil}}}}); err != nil {
+				{Target: "apiid", Name: validation.Pattern, Rule: `^[^*#&+:<>?]+$`, Chain: nil}}}}); err != nil {
 		return result, validation.NewError("apimanagement.ProductAPIClient", "CreateOrUpdate", err.Error())
 	}
 
@@ -218,7 +220,8 @@ func (client ProductAPIClient) CreateOrUpdateResponder(resp *http.Response) (res
 // resourceGroupName - the name of the resource group.
 // serviceName - the name of the API Management service.
 // productID - product identifier. Must be unique in the current API Management service instance.
-// apiid - API identifier. Must be unique in the current API Management service instance.
+// apiid - API revision identifier. Must be unique in the current API Management service instance. Non-current
+// revision has ;rev=n as a suffix where n is the revision number.
 func (client ProductAPIClient) Delete(ctx context.Context, resourceGroupName string, serviceName string, productID string, apiid string) (result autorest.Response, err error) {
 	if err := validation.Validate([]validation.Validation{
 		{TargetValue: serviceName,
@@ -230,9 +233,9 @@ func (client ProductAPIClient) Delete(ctx context.Context, resourceGroupName str
 				{Target: "productID", Name: validation.MinLength, Rule: 1, Chain: nil},
 				{Target: "productID", Name: validation.Pattern, Rule: `(^[\w]+$)|(^[\w][\w\-]+[\w]$)`, Chain: nil}}},
 		{TargetValue: apiid,
-			Constraints: []validation.Constraint{{Target: "apiid", Name: validation.MaxLength, Rule: 80, Chain: nil},
+			Constraints: []validation.Constraint{{Target: "apiid", Name: validation.MaxLength, Rule: 256, Chain: nil},
 				{Target: "apiid", Name: validation.MinLength, Rule: 1, Chain: nil},
-				{Target: "apiid", Name: validation.Pattern, Rule: `(^[\w]+$)|(^[\w][\w\-]+[\w]$)`, Chain: nil}}}}); err != nil {
+				{Target: "apiid", Name: validation.Pattern, Rule: `^[^*#&+:<>?]+$`, Chain: nil}}}}); err != nil {
 		return result, validation.NewError("apimanagement.ProductAPIClient", "Delete", err.Error())
 	}