Merge pull request #1450 from lifubang/servicelsdoc

fixes id and name filter in service ls is the prefix not a part

docs/reference/commandline/service_ls.md

@@ -62,7 +62,9 @@ The currently supported filters are:
 
 #### id
 
-The `id` filter matches all or part of a service's ID.
+The `id` filter matches all or the prefix of a service's ID.
+
+The following filter matches services with an ID starting with `0bcjw`:
 
 ```console
 $ docker service ls -f "id=0bcjw"
@@ -110,9 +112,9 @@ w7y0v2yrn620        top                 global              1/1
 
 #### name
 
-The `name` filter matches on all or part of a service's name.
+The `name` filter matches on all or the prefix of a service's name.
 
-The following filter matches services with a name containing `redis`.
+The following filter matches services with a name starting with `redis`.
 
 ```console
 $ docker service ls --filter name=redis