It relates to non-proportional ri, yes. Reinstatements are sometimes referred to as sideways cover (as you can think of them as multiple limits of cover lined up next to eachother), so vertical cover just refers to the limit. 
(Maybe you could say proportional ri gives unlimited sideways cover, but it’s a term usually referred to only in the context of non-proportional ri).
Last edited by a moderator: Aug 16, 2012
