802.10 is a FDDI spec. Are you sure this is the spec you want to refer to?
Normally 802.10 spec allows for FDDI interfaces to be a trunk/transit for Ethernet and other VLAN types. Mostly done on switches.
Here is a link on 802.10:
http://www.cisco.com/warp/public/537/6.html
What device are you configuring subinterfaces on? Can you share the config portion that you question to this forum can help you more?
Hope this helps you,
Don