Where to Tag VLANs on the F5

Hi,

I'd like to use a single interface on the F5 to transport the external [XX] and internal [YY] VLANs. That interface is going to be connected to a single interface on a Cisco switch, obviously configured as trunk [switchport trunk allowed vlan XX,YY and switchport mode trunk].

Where should I tag on the F5 with XX and YY: on Tag [by default is 4093 and 4094] or Customer Tag under the VLAN set up?

Thanks.