Your task
The messy export has R02 channel " store ". Define a safe correction. Describe the risk of an automatic correction.
Hint
Distinguish formatting fixes from changes in business meaning. Specify what evidence authorizes each correction.
Worked solution
Retain channel_raw, apply trim plus a reviewed case mapping to Store, then check the allowed set {Web,Store}. Reject an unexpected value such as wholesale rather than mapping it silently to Store.
What to hand over
Provide raw source fingerprint, old/new values, rule, evidence, affected row IDs and validation totals. A clean-looking table alone is insufficient.
Try the activity before reading its reference. Keep your sources, commands and assumptions with your work. Companion activities are unsaved self-practice and do not award a certificate or change lesson progress.