The em dash with no spaces on either side (or using thin spaces): A---B or a custom macro, resulting in something like ‘A—B’
The en dash with spaces on both sides: A -- B, resulting in something like ‘A – B’
Currently the book uses A --- B (‘A — B’), which is a bit weird. . . . I personally like em dashes without spaces, which is also the convention followed by most US presses and some famous UK presses (like Oxford University Press).
The usual convention of sentence dashes is either
A---Bor a custom macro, resulting in something like ‘A—B’A -- B, resulting in something like ‘A – B’Currently the book uses
A --- B(‘A — B’), which is a bit weird. . . . I personally like em dashes without spaces, which is also the convention followed by most US presses and some famous UK presses (like Oxford University Press).