The DMV page to apply for a state ID or driver's license in Illinois states that you need to bring proof of your date of birth to obtain an ID card. It links to an acceptable documents PDF which under Group B specifies that an "Illinois Driver's License" is one acceptable form of identification among a handful of others. It does not list out of state identification. Below this list it states
Group B documents must contain the applicant’s full name and complete date of birth and must be verifiable. To be verifiable, it must be possible to contact the regulatory authority to confirm the authenticity of the document.
The PDF specifically says "Illinois Driver's License" but my out of state license lists my full name, date of birth, and it certainly seems like it should be verifiable by their definition. Can an out of state license be used as proof of date of birth? If it cannot be used, why?