The only misinformation in this thread is yours.
http://www.nrmp.org/res_match/policies/map_main.html#indep_apps
2.2.2 Independent Applicants
The term "independent applicant" refers to an applicant who is either:
(a) A physician who is a graduate of an LCME-accredited medical school;
(b) A student enrolled in, or a graduate of, a medical school accredited by the Committee on Accreditation of Canadian Medical Schools;
(c) A student enrolled in, or a graduate of, a school accredited by the American Osteopathic Association;
(d) A student enrolled in, or a graduate of, a school not accredited by the LCME, the Committee on Accreditation of Canadian Medical Schools, or the American Osteopathic Association; or
(e) A student enrolled in, or a graduate of, a Fifth Pathway program.
http://www.nrmp.org/res_match/policies/map_main.html#apps_withdraw_byapps
2.4 Withdrawals
2.4.1 Withdrawal by the Applicant
Independent applicants may withdraw from the Matching Program, but only if the NRMP receives their withdrawal request prior to the rank order list certification deadline through the Match Site Withdrawal screen for the Matching Program.
Applicants who have accepted a residency position through any other national matching service or by agreement outside the Matching Program shall not rank a concurrent year residency position. If an applicant ranks a concurrent year position, he/she will be in breach of this Agreement and may be subject to the penalties described in Section 7.0.
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1) Independant applicants can sign outside the Match *while* participating *in* the Match, so long as they withdraw from the Match before the deadline for certifying their Rank Order List.
2) Independant applicants *include* DOs and graduate USMDs.
I just went through last year's match and participated in both the DO and MD matches, though I withdrew from the DO match and continued with the MD match as an independant candidate. So, I'm pretty familiar with the rules of both matches *and* the specifics of being an independant candidate for the MD match.
Fact-check before you dismiss someone's post. You would think as a conscientious med student, you would know by now that false data is worse than no data, or how to recognize when your personal bias is interfering with your critical thinking skills.