Cisco Wireless :: Configuring H-REAP Local Switching On The WLAN?

I'm reading up on H-REAP in the Deploying and troubleshooting Cisco Wireless LAN Controllers book (Chapter 13) and I would like some clarification on the except below.:"Also notice that, as part of the WLAN configuration, no mention was made of choosing and interface for the WLAN. Unless you will have APs in local mode servicing a WLAN configured for local switching in conjunction with H-REAP APs, the controller interface is irrelevant because the controller will not bridge the client traffic on the network.The H-REAP performs that function.  Even if you will not be using any local mode APs, you must choose an interface to be associated with your WLAN.  In this case, you could use the management interface or create a quarantine VLAN interface, for example if you do not want client traffic to be bridged by the controller if the client traffic is no longer locally switched."Our corporate office has 2 5508 controllers and 150+ APs in local mode.  I'm preparing to deploy a couple of H-REAP APs to a remote site to test.  Is this saying you have to choose an interface when creating a WLAN, but if the WLAN will only be used by  H-REAP APs w/ local switching it does not matter which interface is used when creating the WLAN.  If there are APs in local mode using the same WLAN, the interface the WLAN associates with needs to be on the same subnet as the devices connecting the the WLAN?