How to un-traverse a cross-reference in Microsoft Word on a Macintosh?

Incredibly, the Go Back command in Word for Mac is named "GoBack." The default keyboard shortcut on a Mac is SHIFT F5. (SHIFT FN F5 if you don't have an extended keyboard).

To change the keyboard shortcut (I've changed it to COMMAND LEFT-ARROW):

• View > Toolbars > Customize Toolbars and Menus..."
• Press the "Keyboard" button in the lower right corner of the dialog box
• From the "Category" list on the left, choose "All Commands"
• From the "Commands" list on the right, choose "GoBack" (or click in the list on the right and start typing "GoBack"
• Enter your new keyboard shortcut below.
• Click "ASSIGN" This is not the "OKAY" button.
• THEN click "OKAY."

Adam mentions the WebGoBack command, and this seems to do the right thing. In Word 2011, WebGoBack is not listed in "All Commands" in Tools->Customize keyboard..., so you cannot assign a keystroke to it in there, but it does exist.

Whether it is missing from the "All Commands" list deliberately (e.g. because it's unreliable or unsupported) or accidentally, I cannot tell you. But you can create a macro in Normal.dotm that invokes it, and assign a keystroke to that:

Sub myWebGoBack
WordBasic.WebGoBack
End Sub

or you can use a one-off piece of VBA to assign the command to a keystroke. e.g., this code assigns the command to the Option+Left Arrow key:

Sub AssignOptionLeftArrowToWebGoBack()
  CustomizationContext = NormalTemplate
  KeyBindings.Add KeyCode:=BuildKeyCode(37, wdKeyOption), _
    KeyCategory:=wdKeyCategoryCommand, _
    Command:="WebGoBack"
End Sub

If you would rather use a different key, use a different Keycode - e.g. to assign Option+comma (on my keyboard the "<", which I can think of as a left arrow, is above the ",") you can use:

Sub AssignOptionCommaToWebGoBack()
  CustomizationContext = NormalTemplate
  KeyBindings.Add KeyCode:=BuildKeyCode(wdKeyComma, wdKeyOption), _
    KeyCategory:=wdKeyCategoryCommand, _
    Command:="WebGoBack"
End Sub

To clear all the assignments to WebGoBack (so that Option-Left Arrow reverts to its "word left" function, you can use

Sub ClearWebGoBackKeyBindings()
Dim kb As KeyBinding
CustomizationContext = NormalTemplate
For Each kb In Application.KeyBindings
  If kb.Command = "WebGoBack" Then
    Debug.Print kb.KeyString
    kb.Clear
  End If
Next
End Sub