I have read every word in this terrific thread, Thanks Mike C. for starting it.
All the respondents seem to agree that ANZAC/Anzac usage actually came from the Gallipoli Campaign.
Not so,
It was coined as a time saver during January 1915 in Egypt.
I have gone to:-
"THE OFFICIAL HISTORY OF AUSTRALIA IN THE WAR OF 1914-1918
VOLUME I
THE STORY OF ANZAC"
By C.E.W. Bean
(1921)
Page 124 says that it was coined as a Code word to shorten the long "Australian and New Zealand Army Corps" headings then being used.
Thanks to the following:- Lieutenant A. T. White, who suggested it to Major C.M.Wagstaff who passed the suggestion on to Birdwoods staff and also Sgt. G.C.Little who first asked Sgt. H.V.Milligton to
"throw him the ANZAC stamp".
This Volume I, the first part of the 13 Volume history of WWI. (There are an average 741 pages to each volume). There are mentions of the Australian & New Zealand Army Corps numerous times BEFORE page 545. On page 545 of that first volume is the first mention of the word Anzac, at Anzac.
" About April 29th - the day upon which Sir Ian Hamilton first visited the headquarters of the Army Corps - General Birdwood asked that the Beach between the two knolls, being the original landing-place, should be known as "Anzac Cove" and the name "Anzac" till then the code name of the Army Corps, was gradually applied to the whole area."
see this attachment.
Further into that actual history in Volume IV. there is a map on page 740, (
1030 pages in this volume), is both usages of the word. ANZAC is used as a Code on the map and Anzac as a noun so you know who is being referred to. see here
This is our Official history and therefore this is the correct spelling and usage of the word and all other arguments are unnecessary.
Maybe we need to educate the media.
Regards Rick.