Registration
The World War I draft consisted of three separate registrations.
First Registration. The registration on 5 June 1917, was for men aged twenty-one to thirty-one—men born between 6 June 1886 and 5 June 1896.
Second Registration. The registration on 5 June 1918, was for men who had turned twenty-one years of age since the previous registration—men born between 6 June 1896 and 5 June 1897.
Men who had not previously registered and were not already in the military also registered. In addition, a supplemental registration on 24 August 1918, was for men who turned twenty-one years of age since 5 June 1918.
Third Registration. The registration on 12 Sept 1918, was for men aged eighteen to twenty-one and thirty-one to forty-five—men born between 11 Sept 1872 and 12 Sept 1900.
Registration Cards
Each of the three separate registrations used a slightly different version of the draft registration card. Because different cards were used, the information included in each varies.
In general, the registration cards included the following information.
Full name
Home address
Date and place of birth
Age, race, and country of citizenship
Occupation and employer
Physical description (hair and eye color, height, disabilities)
Additional information such as address of nearest relative, dependent relatives, marital status, father’s birthplace, or previous exemption from service
Signature
The card used for the first registration (sometimes called the Twelve-Question card because of twelve questions on the front) includes this information: name, age, address, date and place of birth, citizenship status, employer’s name and address, dependent information, marital status, race, military service, and physical appearance.
SOURCE:
http://search.ancestry.com/search/db.aspx?dbid=6482(scroll down past search form, info near bottom of page; there is other WWI Draft Reg Card info )