[summary: A message singling out one thing from a set of $~$n$~$ is sometimes called an $~$n$~$-message. For example, a message singling out one thing from a set of 13 is a 13-message. An $~$n$~$-message carries $~$\log_2(n)$~$ bits of information.]
A message singling out one thing from a set of $~$n$~$ is sometimes called an $~$n$~$-message. For example, a message singling out one thing from a set of 13 is a 13-message. An $~$n$~$-message carries $~$\log_2(n)$~$ bits of information. For a formal account of what it means for a message to "single out one thing from a set of $~$n$~$," see Information.