I asked this question of Customer Support and got this answer:Fields on the Ticket
Details built-in form or a Custom Form with defined variables can be built with
this format. This variable format will also pull any meta-data associated with
the tickets. %{ticket.field variable}
Fields on the Ticket Details built-in form or a Custom Form involving a Custom
List with defined Properties can be built with this format: %{ticket.field variable.property variable}
So I assumed, since my question was about Canned Responses, it would work. I could not get it to work until I read a comment by ntozier stating that variables had to be in lower case. That solved the problem. Thanks to all for the help.