Difference between the 1904 and the 1913 edition

Observation by Saulo de Oliveira Cantanhêde:

In the introduction of the 1913 version, Mark 1:1 was added to the category of “a passage for which ancient authority is in part wanting” (labeled with the symbols < >), as John 5:3, 4 and John 7:53-8:11 were marked as well.

See also the comparison of the introductions found in the 1904 and 1913 editions, shown side-by-side in the following image.