Unfortunately, there's nothing in the field code you can edit. If you select one of the fields and press Shift-F9, you'll be able to see the field code - and it won't have 'Figure', 'Table' or any other indicator of the caption type. If you were to use Find/Replace on the field
results, that would be ineffective, as the fields will revert to their original display as soon as anything causes the cross-references to update. The only way around that - and it could be useful when the document is at it's 'Final' stage, would be to edit the display via a macro, then either lock or unlink the fields. The following macro uses a 'lock' approach, so that the references can be updated later on (by re-running the macro) if need be:
Code:
Sub AbbreviateCaptions()
Dim Fld As Field
For Each Fld In ActiveDocument.Fields
With Fld
If Left(.Result.Text, 6) = "Figure" Then
.Locked = False
.Update
.Result.Text = Replace(.Result.Text, "Figure", "Fig.", 1, 1)
.Locked = True
End If
End With
Next
End Sub