diff --git a/deploy.md b/deploy.md
index 156205fe..64ecadfb 100644
--- a/deploy.md
+++ b/deploy.md
@@ -65,8 +65,8 @@ services:
 
 #### constraints
 
-`constraints` defines a required property the platform's node must fulfill to run the service container. It can be set either
-by a list or a map with string values.
+`constraints` defines a required property the platform's node must fulfill to run the service container.
+See example usage [here](https://docs.docker.com/reference/cli/docker/service/create/#constraint)
 
 ```yml
 deploy:
@@ -75,30 +75,16 @@ deploy:
       - disktype=ssd
 ```
 
-```yml
-deploy:
-  placement:
-    constraints:
-      disktype: ssd
-```
-
 #### preferences
 
-`preferences` defines a property the platform's node should fulfill to run service container. It can be set either
-by a list or a map with string values.
-
-```yml
-deploy:
-  placement:
-    preferences:
-      - datacenter=us-east
-```
+`preferences` defines a strategy (currently `spread` is the only supported strategy) to spread tasks evenly 
+over the values of the datacenter node label. See example usage [here]https://docs.docker.com/reference/cli/docker/service/create/#placement-pref)
 
 ```yml
 deploy:
   placement:
     preferences:
-      datacenter: us-east
+      - spread: node.labels.zone
 ```
 
 ### replicas