The Feature List contains the following paragraph on Visual Filter documents:
Visual Filter documents - Want to highlight all the "therefores" so you can see what they are there for? Want to rearrange the Greek text (or even the aligned English!) to start a new line at every conjunction? Almost any search can be preserved as a visual filter assigned your choice of color and style. You can turn it on and off as you please.
It's one of the visual filters...
it's the same with "therefore" just type it in...
