[Jeff Davis offers two options for commenting Excel formulas](http://www.techrepublic.com/article/an-unconventional-way-to-comment-your-excel-formulas/1032346). The first way is the obvious comment feature, but this has downsides. The most notable downside is the red arrow that is present in the corner of the cell — something that would lead most people to worry that there is a calculation error on that cell.
It’s a decent way around the problem, but since the comment exists only as a comment function, and not as part of the formula, it is easily missed when editing the formula.
The second option that Davis mentions is by using the `N Function` — something I had never heard of before. Basically this is a hack that allows you to type a string into a formula which will always return `0`. So adding `+N(“My comment”)` will only add a `+0` to the formula. This is a really clever solution and exactly what I was talking about.
But, it does have one huge downside: it isn’t supported in Numbers.
For many this won’t matter, but Numbers removes the formula all together and simply shows the solution value. At my office we use Numbers for a few reports (rarely switching between Excel and Numbers) and it is a bit worrisome that your spreadsheet could stop being dynamic if a Numbers user opened it.
For our complex, internal, spreadsheets the N function looks like a great, albeit hack, solution.