What is the meaning of [A nod’s as good as a wink to a blind horse]

“Usually suggesting that a person understands very well what another person is getting at as any kind of hint or gesture will suffice to communicate it.”,Source for proverb and meaning; George Latimer Apperson (May 2006). Dictionary of Proverbs. Wordsworth Editions. p. 413. ISBN 978-1-84022-311-8. Retrieved on 16 September 2013.