The first digit stores the database name display preference:
1 = Title 2 = Filename 3 = Title and Filename 4 = Filename and Title
The second digit determines the Read database when.. setting:
1 = Read Database Immediately Upon Selection 2 = Read Database Only After 'Apply' Button is Clicked
So if the notes.ini entry was set to "42" it would mean that database filenames and titles are displayed and that database information will only be read after the 'Apply' button is clicked.