The individual tunes are in files with names of the form NNN_Title.abc, where NNN is the 3-digit tune number, and Title is the tune's title. Initial articles in the titles are all lower-case, to make it easier for software to skip over them by using the simple rule "Start with the first upper-case letter. In a few cases, the first significant word of a title has been capitalized to fit this pattern. Also, accents aren't used in the file names (though they are in a few titles inside the files).
There are a few tunes that use some of ABC features that have recently been introduced, such as grace notes with lengths. A lot of "version 1" ABC software may not understand these features, so at attempt has been made to transcribe such tunes in a way compatible with the older software. These files have names ending in "-V1.abc" and "-V2.abc", and the '_' after the tune number has been changed to '-' or '=' to make it easy to distinguish them in the Makefile. This applies to the "all tunes" files, too, of course.
The tunes are gathered into two "all tunes" files, named SCAJMR1.abc and SCAJMR2.abc; the initial articles in these files have been capitalized to better match the capitalization used in the book (which is somewhat inconsistent).
The book uses staff layouts that include some odd staff breaks and many short final staffs. Many tunes have the staff breaks reorganized to fit a somewhat small print scale for proofreading. The staff breaks aren't musically significant, and you should rearrange the layout to work best with your musicians. This is especially true if you have people with vision problems.
Most of the tunes in the book use the common repeat scheme of the time with :||: at the very end, and no initial repeat symbols. Many of them have been transcribed to match the current common |: ... :| repeat notation, when the initial repeat symbol only omitted for tunes with a very short initial pickup (1 or 2 notes).