WWI Edition Number

Edition Number

The edition number on a trench map has two distinct parts:

1) a number printed in black

2) a letter printed in red

The black number indicates the version or iteration of the base map
(e.g. topographic information).

The red letter indicates the version of the overprint information
(e.g. trenches, guns, enemy defences, etc.)

The image below is taken from the top margin of a trench map.