How can I include text (intended to be a comment) in a numeric
formula?

Effectively, I would like to write something like the following:

=A1 - A2 # this is the comment

My goal is for the comment to be visible only when I look at the cell,
but the cell retains its numeric quality. That is, in the example
above, the cell evaluates to A1 minus A2, and other numeric formulas
can refer to it straight-forwardly.

I know that I can do "insert comment", but that is not what I want.

I know I can do the following:

=A1 - A2 + N("this is the comment")

But I thought there is a more straight-forward way to do it.