Associations return in Assassin's Creed Syndicate. Once again, the Fryes can cater to groups to earn special rewards as seen in previous Assassin's Creed Games. This is introduced in the Sequence 3 Memory, Abberline, We Presume
By completing special missions, tasks and objectives for specific people and groups, their loyalty to the Rooks. When their loyalty becomes a particular level, you will unlock unique rewards.