Facebook Open Graph locale for Australia

I am trying to add the og:locale tag for an Australian website and Facebook's linter tells me that I have an error.

Based on the documentation (and assuming what the correct content should be), I have added this to my page head:

<meta property="og:locale" content="en_AU" />

Facebook's linter (开发者_如何转开发 http://developers.facebook.com/tools/debug ) tells me:

Object Invalid Value Object at URL 'http://foo' of type 'website' is invalid because the given value 'en_au' for property 'og:locale:locale' could not be parsed as type 'enum'.

What's going on here? Is en_AU not the correct code for australia? I also tried en_AUS and that didn't work either. If i change it to en_US it works fine.

See FB's i18n documentation for help. More specifically there is a complete list of supported locales. Unfortunately Australian English isn't awesome enough to be considered as a separate thing; you'll be choosing between UK and US English.