The printer of the source document used (almost) identical characters for number zero and lower-case letter o, which may have led to errors in the transcriptions of some of the the coded messages. The same applies to some instances of capital letter I and number 1.

Except as mentioned under Changes below, all advertisements have been transcribed verbatim, including inconsistencies, obviously missing punctuation, and obvious typesetting, spelling, factual or other errors, as they may have been inserted deliberately or may in some instances constitute (part of) a code. In addition, it is not clear where errors originated: in the original newspaper advertisement or in the transcription to or the printing of the book. The non-English advertisements in particular are full of (possibly deliberate) errors.

Changes made:

Advertisement headings (number and date) have been standardised to be entirely in italics.

No. 12: ... eyes,.it is ... changed to ... eyes, it is ...;

No. 127: Period inserted after first capital M;

No. 261: comma inserted after May 1;

No. 598: missing hyphen in mitge bracht assumed (changed to mitgebracht);

No. 695: 1876 changed to 1856.