I want to create an if statement that returns the value from a cell if all parameters are true. Basically, finding for field 4, it’s an "if the checkbox in field 1 is yes and the invoice paid date in field 2 is after 12/31/18 and before 1/1/20, then ...

I’m wanting to clean up our primary base (eliminating unused fields, etc). Is there a way I can see whether a field is being referenced as a lookup, link, or part of a rollup so that I don’t accidentally delete it? Thanks! Tricia