Originally published at: http://www.howtogeek.com/162231/add-comments-to-formulas-and-cells-in-excel-2013/
When entering formulas in Excel, you may want to remind yourself, or someone else, what it was for in the future. Or you may want to add instructions to let users of your spreadsheet know what to do in certain cells.
You need to make sure you understand what is going on here... Your suggestion evaluates to adding 0 to your formula. So, this only works in places where adding a value to your formula is applicable. You should clarify this in your how-to.
You state that the N() is to add comments -- that is false. It is a function to evaluate the value to a number.It converts non-number values to numbers, dates to serial numbers, true to 1 and anything else to 0. This is not, by any means, designed to store comment code.