SuDoc numbers for Congressional commissions and committees (Y3. or Y4. respectively) have a slightly different format. The number following the Y3. or Y4. is a Cutter number composed of letters and numbers. These documents will be shelved alphabetically and then numerically by the Cutter number.
In many cases, the Cutter number is followed by a slash and one or more numbers. The additional numbers with no dash come before the same number with a dash.
Y 4.F 49: 96-89
Y 4.F 76/1: 94-36
Y 4.J 89/1: 98-100
Y 4.J 89/2: 99-10
Y 4.J 89/2-10: 984
Y 4.J 89/2-11: 979
After the colon, several types of book numbers are used: dates, numbers, volumes, and Cutter numbers. Usually only one book number is used. However, if both letters and numbers are used for the same class number, the lettered documents will be shelved before the numbered ones.
Y 4.C 73/7: AD 65
Y 4.C 73/7: 104/24
Y 4.C 73/8: M 55/2
Y 4.C 73/8: S. Hrg. 105-65
Y 4.C 73/8: 97/16
