This is a notation in the margin to indicate if there was a correction or continuation of the main body of the document. Many times it's due to not enough space to complete the information in the body so it is continued in the Margen. Or they may add the year of appearance, page number, registry number and tne name of person and date of birth in the margins. May also be a correction to something that has been stricken and the correct info for the strcken info

While Anton's 'marginalia' is of course the 'correct' term, I always feel its use is rather pretentious in this kind of relatively simple document, where it tends to stick out like a sore thumb.

I actually think think "margin notes" is more natural than "marginal notes."