Cancelled

http://en.wikipedia.org/wiki/Cancelled_(South_Park)

>>Hi everybody,
>>
>>I've checked this link http://grammarist.com/spelling/cancel/ but I am not 100% sure which spelling should I choose. The software is written by US company, but may be used by US, Canadian, NZ and Australian clients. It may also be used internationally in other countries.
>>
>>So, just wondering what spelling do you prefer in your code?
>>
>>Thanks in advance.
>
>
>
>Canceled.
>
>http://books.google.com/ngrams/graph?content=canceled%2Ccancelled&year_start=1800&year_end=2008&corpus=17&smoothing=3&share=