All,
Recently ran into an issue where by I was using a field for a filename, this filename was then used to create a url. Unbeknownst to me, the filename was going to contain 'illegal characters i.e. blank spaces &/\*?<>:'.()[] . The blank spaces issue I already knew about and was 'translating' blank spaces into underscores.
A quick google and I came up with a list of other 'illegal' characters. so my final default value was : translate(Input, " &/\*?<>:'.()[]", ""). That's great. All seems to work pretty well. In my testing, rather than write a rule, I changed my filename text boxy field to a calculated value.
Yet, each time I wanted to change my default formula, I have to un do my calculated value and change it back to text. This got me thinking how can I show the formula in another text of a default value? Not the end result, but the actual formula?
This I think would be really useful for troubleshooting as you're crafting a formula.