From
this thread:-
I found the following, mentions skip button:-
Via Point.
Is used by the Zumo to indicate a point on the route which it will insist that you visit. Unlike the 660, if you missed a point on the route (maybe positioned incorrectly up a side road), but continued towards the purple highlighted route, the 660 would continue navigating once you had reached the purple line. The 590 doesn't. It nags you until you have been there - or you can press the skip button. The skip button isn't installed by default, and it is available from the menu button in the bottom right corner. 'Skip' was a added as a later fix to the Zumo software.
Via points will show up in the data display eg as in 'Time to Via', 'Distance to Via'.
The satnav will announce - visually and audibly - your approach to and your arrival at a Via Point.
The 590 gives a list of all of the Via points on your route when you select a route to follow. But it shows ONLY the Via points. It doesn't show any other points.
Via points on the 590 show up as flags in the route and on the map.