In the file open dialog, there is a check mark for "open read-only".

When a file is open read-only, the window title says "read-only".

But for some extremely obscure (to me) reason, the method for toggling between having a file open as read-only, and open with read-write, is called "edit file".  If the file is already open for writing, the plain meaning of that would be a no-op.

It would make much more sense to label this operation as "toggle read-only" or some other phrase that contains the words "read-only."

In addition, it would be useful if this operation appeared under the "File" menu.

Finally, the help documentation is extremely opaque on the subject of read-only:  "Use the Edit File icon to activate or deactivate the edit mode."

Upon first reading this, I had no clue what "activate or deactivate the edit mode" might mean.  Again, this should use the phrase "read-only."  Also, it would be helpful if the help indicated where I might find this "Edit File icon."
Operating System: Windows 7
Version: 4.2.5.2 release