“c/o” is the sign for “in care of.” It’s utilised when sending a letter or package to someone at another person’s address. It’s also occasionally utilised to deliver mail to a business address.
Correspondence sent “in care of” someone is addressed to the intended recipient with “c/o” under the name, followed by the name of the person or company at the delivery address. The sender simply writes or types a “c” followed by a forward slash and then a “o” whether the mail is addressed by hand or on a computer. The “c/o” symbol can also be made on a computer by selecting “Insert” and then “Symbol” and entering the code 2105.