A ```suggestion block in a diff comment proposes replacement lines for the anchored range (--start-line for ranges), shown as a diff on the page and in mr threads. mr apply-suggestion <n> <thread> commits it to the source branch as the applier: server-side through CheckPush, a CAS ref update and the post-receive work (now control.RefsUpdated, so CI, events and the merge queue see it), within the owner quota; on repositories requiring signed commits the CLI applies, signs and pushes locally. Stale anchors, renamed or deleted files are refused. The thread resolves only for those who may resolve it. repo commit-file checks the quota too. Suggestion anchors read through one cat-file --batch per render. Migration for line ranges. Parity/Users/CHANGELOG.
Closes #288