Collectives are on-chain groups hosted on the Polkadot Collectives parachain. They enable collaborative decision-making and governance through customizable structures and operational parameters, serving various community and technical functions within the Polkadot ecosystem.

To set up a collective, stakeholders define its purpose, governance structure, and operational parameters such as member promotion/demotion periods, offboarding timeouts, and minimum promotion periods. A new instance of the collective pallet is added to the runtime with these parameters. Multiple pallets may be used for specialized logic, such as ranked membership and salary management.

Key parameters include Demotion Period (time to demote a member), Minimum Promotion Period (minimum duration before promotion), and Offboard Timeout (time allowed for offboarding a member). These can be tailored to each collective's needs.

Yes, collectives may require members to submit evidence to retain their rank or role. The guidelines for evidence submission are defined by the collective and help ensure transparency and accountability.

Collectives can operate sub-treasuries to fund their activities and allocate salaries to members, enabling independent operation while contributing to the broader Polkadot ecosystem.