I should clarify about proper topo maps, since Gab IZ1KSW asked specifically about this
(I guess this might be of interest for anyone who calculates summit prominences and uses topo maps).
I consider the maps with smallest contour interval to be the best, since almost all col heights, and some summit heights, are calculated from the contour lines.
1:25.000 scale topo maps I used, have contour interval of 10 meters. On some areas on the map (but not all), there are 5 m and 2.5 m subdivisions. Still, there are summits where a 1:25.000 map can not give a yes-or-no answer if the prominence is P150, so those summits are discarded, left to be checked with better maps or with GPS some day.
Larger scale maps (1:10.000, etc) are clearly much better. Those who have access to them are really lucky!
1:50.000 scale maps look fine at the first glance, but if the contour interval is 20 meters (as it is in my country), these maps are not the best choice.
73 Fric YU1WC