How can I use the tags in the SysConfig?

[1soproni]

I would like to set default subject for priority change, close, etc...
I found that I can do it via sysconfig, e.g. Ticket → Frontend::Agent::Ticket::ViewPriority
How can use tags e.g. in Ticket::Frontend::AgentTicketPriority###Subject field?
I should use the same what I get if I click to reply.