Variables which reference other variables in the script
I've had a pesky issue in the past with the dollar expansion. A great feature, but can cause problems if you don't know how to avoid it... I often want to write a large number of variables, which I paste into my script, sometimes using a program like excel to use a formulaic pattern to writing them.
This approach basically tweaks what is being evaluated the first time (by the script) to produce a string which later on when it is evaluated it can repeatedly use the other variable in the front end expressions.
Hope this helps someone else who encounters the same issue.