An O-line (frequently also spelled as O:line; on IRCds that support local operators, the O-lines of those are called o:lines with a lower-case O), shortened from "Operator Line" and derived from the line-based configuration file of the original IRCd, is a line of code in an IRC daemon configuration file that determines which users can become an IRC operator and which permissions they get upon doing so. The name comes from the prefix used for the line in the original IRCd, a capital O. The O-line specifies the username, password, operator flags, and hostmask restrictions for a particular operator. A server may have many O-lines depending on the administrative needs of the server and network.