Cahoots

Cahoots appears to be something of a technical term among the trolls of Alternia. Given that Alternian culture espouses looking out for number one, long term cooperation is difficult to sustain. Instead, the trolls seem to occasionally 'be in cahoots' with one another, suggesting a short-term alliance that will last until it is beneficial for one troll to betray the other.

Cases of Cahoots
Most cases of being in cahoots are alleged, with one troll accusing another of it. There are however some cases in which cahoots are openly admitted.

Karkat and Jack
Karkat and the troll session of Jack Noir have HS 004026 (elected to be in cahoots) in a mutually benefical scheme to banish the Black Queen after Jack revealed to Karkat that they share a common color of blood, a shock to Karkat as his candy-red blood is an anomily in Alternia. When Bec Noir arrives in the troll session, Karkat is genuinely shocked and hurt when he recognizes Jack and believes their alliance has been broken.

Vriska and EqUius
Vriska and Equius choose to be inHS 004122 (Cahoooooooots.)while the troll teams were being assembled, planning to curry favour with Aradia through the present they had created for her and then usurp her position as leader of the team. Vriska reveals her paranoid nature, insisting that there will be no double-crossings while trying to read Equius' mind. While he plays along with the plan, he punishes Vriska by forcing her to hit herself with her robotic arm. It is revealed that both plan to betray their scheming partner.