Change Case
You can change the case of selected text from upper to lowercase and back. You can also change the case to Sentence Case ( first word at the beginning of a sentence to uppercase case), and/or to Title Case (first letter of each selected word to uppercase).
To change text, highlight a selection.
If no selection of text is made in the Edit window, capitalization of the word, to the right of the cursor is changed.
- Choose Edit > Change Case…. A dialog box appears. Choose the radio button for the case desired and click OK.

- The dialog box disappears and the text you selected is changed.
To toggle through all the choices, use Shift+F3. The selected Text will change to the next case. An additional Shift+F3 will toggle to the next and continue until the desired results. Note: There is a bug in Editor 5.3 that won’t change a letter that is next to a parenthesis.


Excellent! Thanks for the tip!
I found in Arbortext 5.4 that Shift-F3 is already mapped to toggle case and CONTROL-SHIFT-A toggles upper case specifically.