It looks like the "black badges" are
Discovery's version of the
Night's Watch.
The Night's Watch is a military order. . . .
Joining the Watch provides absolution for past crimes and immunity from further punishment. Brothers start with a clean slate and can rise within the ranks whatever their origins.
[. . .]
Men of the Watch dress entirely in black, giving rise to the nickname "crows".
[. . .]
"Once a man has taken the black, he is beyond reach of the law. All his past crimes are forgiven."
―Maester Luwin
The Night's Watch has no heraldic symbol, to emphasize its sworn duty to be removed from petty politics of one lordly House or another, but to defend the lands of men as a whole. Thus, the Night's Watch uses solid black on its banner and shields, which symbolize the erasure of any allegiance to noble Houses.
Section 31?
The new Klingons are the
Thenns (a.k.a. "the Thenn"):
The Thenn people (alternatively referred to as "the Thenn") are the most advanced and best equipped of the wildling tribes, as well as the most disciplined. Thenns also shave their heads bald and engage in self-scarification as well as cannibalism, feasting on the flesh of their enemies.
