NATO style map symbol for special operations infantry.
I have seen no reference for this in any edition of APP-6 nor in FM 101-5-1/MCRP 5-2A, but it does appear in several war gamer sites.
<a href="//commons.wikimedia.org/wiki/User:CdnMCG" title="User:CdnMCG">CdnMCG</a>
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<span class="int-own-work" lang="en">Own work</span>