ICO Acronym

Meaning	In care of
Popularity
Usage	Email
Description	Specifies the person who a message or letter is for, i.e., a letter may have the phrase "ICO John," which means it is intended for John.
Example	"It says "ICO John" on it, so you should open it, John."
Updated: December 21, 2010

Meaning	In concern of
Popularity
Usage	Email
Description	A shorter way of saying a matter concerns a specific person.
Example	"ICO Sarah, we should ask her if she has any feedback so far."
Updated: December 21, 2010

http://www.chatslang.com/meaning/ico