Reserved tokens allow a project to guarantee that a percentage of all newly minted tokens from payments will be reserved to a preprogrammed list of JBSplits. This percentage is referred to as the reserved rate.
A project's reserved rate and reserved token splits can be reconfigured each ruleset.
Reserved tokens do not get minted automatically when a new payment is received. Instead, they must be explicitly distributed using the JBController4_1.sendReservedTokensToSplitsOf(...) transaction.