How to do change bars under nroff ?

[Robert Heath]

Do any of you nroff gurus know how to create change bars under nroff ?
By change bars I mean a visible indication, usually a bar in the margin,
that new material has been added or changed since the last 
revision of a document.

We typically run nroff with ms or mm macros under System 5.2.

Please reply by mail and I'll summarize to the net.

	Thanks,
	Robert Heath
	heath at ncrcae.Columbia.NCR.COM