Has anyone gotten en-US or other two-level language browser settings to work?

[Jonathan Simonoff]

I've been trying to get Confluence to obey the browser US English setting to work. In some cases, the browser is obeyed -- such as if I change my language to French. It occurs to me that perhaps the problem is that Confluence only pays attention to the first part (en) of the language code, and ignors the "US" part. Does the browser setting alone (with the user's language setting in Confluence set to obey the browser setting) work for such seconday language settings for anyone? (That would be valuable info for me, because if it does work in other situations, then the problem may be in the way that the US language pack specifies the language code.)

FYI, if I change my user setting within Confluence explicitly to US English, the language pack does work.

[Jonathan Simonoff · Accepted solution]

It isn't clear if this applies to all two-level codes (such as Canadian French), but at least for US English it is a known bug: https://jira.atlassian.com/browse/CONF-23220#comment-350883.