quotes...."" .....seems to be difficult to manipulate manually

[webmasterpdx]

I notice that if you try to put "" around some expressions, characters disappear, and it can be difficult to place strings around them.

e.g. Put the cuberoot of x in CAS mode and now try to put "" on both sides of the expression, and try to delete one of the " characters on either side....it gets messy. It changes the cube root to NTHROOT, etc, etc....

Is this documented any place?