Short for in the care of or similar phrase.
Care of, usually abbreviated as ℅ on envelopes, signifies an intermediary who is responsible for transferring a piece of mail between the postal system and the final addressee. For example, when the addressee has no standard address, is under a corporate mail system, or is being manually forwarded mail sent to a more accessible location. In Australia and New Zealand c/- is often used in place of ℅.
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