Correcting a Region: four worked corrections, one per cause
Correcting a Region: the page the fixer's Guide button has been pointing at The Guide button in fixer.html, its help text, and tools/README.md have all linked to this page since the fixer shipped, and it was never written -- so the button landed on the wiki's "Create new page" screen. What it covers: what a correction corrects and the three inputs a wrong region comes from; opening the fixer from the published page, a clone, a phone, or MATLAB; the five tools and their keys; the four causes and how each looks under Pick; Inspect, Recut and QC image, and why they are off on the published page; Commit, the token, and the dry run; and what the Apply correction workflow does with the branch afterwards. Listed in the sidebar and on Home under a new Contributing heading.