I sure everyone is fed up with the same question and the multiple copies of
D.P. response.
Let's try a little twist.
Many Workbooks, each having a number of worksheets.
One sheet to have outline feature.

D.P.'s solution would work for many who have written in, if it can be
modified in such a way, that the selection of the + or _ would actually
trigger the password(s) off, do requested procedure, then trigger password(s)
on.
Feasible?

My personal application is a little more complex.
I have a number of different protection off, protection on icons on my
custom toolbar. Each set uses different pass-words and those passwords are
changed with some regularity. Therefore, in order to make this work, I
would have to drop all but one of my pass-word sets, and set/change the
password in each of the files everytime the passwords were changed. Not
feasible.

Does anyone know of a third party add-in that may meet my requirements?

Thanks in advance for your help.
Even that, for my application is not up to snuff, since I have a number of
icon shortcuts to protect/unprotect my sheets. Therefore,