Pretty sure it's your social security number. (takes a day or so for the system to figure out that you're eligible though after you initially register for an exam)

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CLEPS:
Social Sciences and History
College Math
English Composition (no essay)

DANTES:
World Religions
Civil War and Reconstruction
Drug & Alcohol Abuse
Management Information Systems

Excelsior:
Organizational Behavior
Ethics: Theory and Practice
World Conflicts since 1900
World Population

All done! 42 credits by exam