Although SIOR did respond to the SEC (thanks for pointing that out), they simply agreed to the SEC's penalty of revoking the stock as they likely had no defense for not filing periodic reports since 2010.
Referrring to a revocation as "voluntary" indicates that a company chose to revoke its stock -- not that it was a result of regulatory action. That is not the case here. SIOR stock was going to be revoked.
SIOR simply did not object to its stock to be revoked after an involuntary suspension and Administrative proceeding, both initiated by the SEC.
The fact that they agreed to the revocation does not make it "voluntary."
It's like a criminal pleading guilty and accepting the penalty.
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