Git rerere, meaning "reuse recorded resolution," records user resolutions to merge conflicts and automatically reapplies them on identical future conflicts.

It aids long-lived branches by enabling test merges without history clutter, repeated rebases without re-resolving issues, and re-merging evolving topic branches after test failures. Enable it globally with `git config --global rerere.enabled true`; commands like `git rerere status` and `git rerere diff` show recorded states.