They can actually be used pretty much anywhere, i've seen people use them where they have absolutely no use at all, but the code works fine, eg:

Code:
alias test {
  goto test
  return
  :test {
    echo -a test
    echo -a 1 2 3
  }
}


In fact, I suppose you could use that to name or describe blocks of code without using comments:

Code:
alias test {
  :echo some numbers {
    echo -a 1
    echo -a 2
  }
  :message a few channels {
    msg #chan1 hi
    msg #chan2 there.
  }
}

New username: hixxy