Allow variables to be used in fields

It would be helpful if we could use variables in fields. A few examples would include using the first x characters of the description as the summary.

Another example is, say I have a training request type ticket, now I use Summary = 'Training Request', if I could use something like 'Training Request - $requester - $created', that would provide me a more descriptive summary.

I understand that the queues can be configured this way, but when used in correlation with the JIRA and Agile, it would be pretty neat.