Use conditional formatting to mark formula cells
New Rule, Use a Formula, =ISFORMULA(A1)
Thanks to Craig Brody: mark formula cells that are links to other sheets
New Rule, Use a Formula, =ISNUMBER(FIND("!"),FormulaText(A1)))
Extending this: To mark cells pointing to external workbooks, use
this formula: =ISNUMBER(FIND("]",FORMULATEXT(A1)))
You can use AutoSum in Several Cells at Once
When you are editing a formula in conditional formatting box and press the arrow to move,
you will get cell references. To prevent this, use F2 to change Enter mode to Edit mode