Is it legionnaires' disease, legionnaire's disease, or legionnaires disease?

The recent outbreak of legionnaires' disease reminded me of a common problem many people (including myself) tend to have with spelling. Where do we place the apostrophe? If you check the news articles on the recent outbreak in the Doncaster area you'll find all three spelling variations.

As many of you will know, I'm the person who created the Australian English spellcheck dictionary now used in products like OpenOffice.org, Firefox, Thunderbird, Google Chrome, and in fact, I'd say if you are using an open source product with Australian spelling, you're probably using my work.

I found a couple of problems with the open source path for me. The first thing is I was putting in hundreds of hours and whilst the open source projects were happy to come along and use my work, none gave anything back to support me. The second issue is the original word list was based on an open source dictionary and required over 30% of the words to be culled to start with and the rest to be checked using existing spellcheckers. Unfortunately that meant the dictionary would in general only be a subset of the spellcheckers I used to vet the word list, but worse, any errors would not be picked up. It reminded me of the old expression, garbage in, garbage out. It wouldn't matter how much time and effort I put into patching the word list there would still be a significant number of errors in the list that may take years to find.

I felt it was time to build a quality product and the only way to do that was to start from scratch. I estimate by the time I've built the dictionary to the standard I am happy with, I'll have invested close to a thousand hours, possibly more. I don't know about you, but I certainly can't afford to give away a thousand hours of my time. Of course if each user of OpenOffice.org, Firefox, Thunderbird and Google Chrome who use my work contributed just $1, I could have worked on the dictionary full-time, and kept the work open source. I've found most open source users, business users, and projects, don't want to pay anything and don't give anything back to assist the projects they use.

My work is now limited to clients and those who make a contribution. It is those people after all who enable me to support my family. My work is called the Kelvin dictionary and the public face of my work is Word Check.

The question Is it legionnaires' disease, legionnaire's disease or legionnaires disease?, is the type of question I am aim to answer with Word Check. In fact legionairres' disease is one of the terms I'd previously researched and if you enter the three variations, the preferred Australian English spelling will be provided.

The Kelvin dictionary aims to provide the preferred spelling in Australia. The preferred spelling in Australia is legionnaires' disease"

May all your spelling be the preferred Australian English spelling.

- Kelvin Eldridge

NOTES:

The Australian Oxford Dictionary - Second Edition states the spelling as legionnaires' disease.
The Macquarie Concise Dictionary - Third Edition states the spelling as legionnaires' disease with an also spelling of legionaires' disease. (Yes that isn't a typo on my part. That is  in the dictionary.)
The Macquarie Dictionary - Fifth Edition states the spelling as legionnaire's disease with an also spelling of legionnaires' disease.

A check of the various government web sites tends to lean towards the use of legionnaires' disease. At this stage this is the preferred spelling offered by Word Check and Kelvin's dictionary. Kelvin's dictionary aims to make spelling easier by only providing the preferred Australian English spelling as the correct spelling variation.

A check of the overseas based spelling sites generally returns legionnaires' disease as the spelling.

All three spelling variations are commonly found across Australian web sites.

Those using Microsoft Word 2007 will find the grammar checker suggests Legionnaires' disease with capitalisation. Interestingly I see quite a few sites (such as Wikipedia) using the capitalised version. I tend to suggest to people not to rely on Wikipedia as an authoritative resource. My research of words is done against authoritative references. Those using Microsoft Word may tend to change the capitalisation based on Microsoft Word's suggestion. Both the Macquarie and Oxford use the lowercase spelling.