Last modified: 2011-09-20 08:09:09 UTC
...the summary about sums this up. Canadian English is a mix of en_US and en_GB. Plenty of en_US phrases and plenty of en_GB spellings.
Plus occasional inclusions, like [[wikt:en:toque#Etymology 2]].
[[mediawiki:Blockiptext]] could be "Inappropriate blocks can have a chilling affect on a community. Make sure to grab your toque before hitting submit"
What is this bug about? MediaWiki already supports it, but only if it makes sense to have it and somebody does it.
We have no MessagesEn_ca.php nor does Names.php have an entry for en-ca. There's also bug 31015 talking about supporting US / UK spelling differences but no account for CA which is neither all en_US nor en_GB spellings.
And there wont be unless someone is going to supply the data. This applies to all languages: make translations at translatewiki.net and provide patches for things like date formatting, number grouping and so on.