Why there are two special tenants named as "service" and "services" created in Openstack deployed using RHOS Director

Issue

In the Overcloud/UnderCloud created by using Director to deploy RHOSP7, I see there are two tenants named very similarly: a "service" and a "services" tenant:

[stack@director ~]$ keystone tenant-get service
+-------------+----------------------------------+
|   Property  |              Value               |
+-------------+----------------------------------+
| description |                                  |
|   enabled   |               True               |
|      id     | 8674d44aaad2437c96e78cd286420e51 |
|     name    |             service              |
+-------------+----------------------------------+
[stack@director ~]$ keystone tenant-get services
+-------------+-----------------------------------+
|   Property  |               Value               |
+-------------+-----------------------------------+
| description | Tenant for the openstack services |
|   enabled   |                True               |
|      id     |  71d4ea18649242c9bf9c67d27eeb7187 |
|     name    |              services             |
+-------------+-----------------------------------+

• Currently both the "services" and "Service" tenant are getting created on the undercloud and overcloud. Why two such
  special tenants needed ?