A question for the respected language code experts in the audience.

Apparently, the Simple English Wikipedia uses "en" as its language code in the HTML lang attribute, etc.

I never noticed it until recently, when it started causing various bugs with the ContentTranslation extension of which I am a developer. I somehow assumed that it uses something like "en-simple" without ever checking it, and that assumption was wrong - it's just "en".

I believe that the code should be different from what is used by the English Wikipedia, like it is with other wikis in language variants, such as be-tarask.

Do you have any suggestions about what code should it be?
Something else?
Should I register anything new with any standards organization? (If I recall correctly, this was done for be-tarask?)
Can I reuse any existing code that would be appropriate?
Is it a bad idea in general and it should be just "en"?


(PS: If you're curious what are the issues, see https://phabricator.wikimedia.org/T110190 )

Amir Elisha Aharoni · אָמִיר אֱלִישָׁע אַהֲרוֹנִי
‪“We're living in pieces,
I want to live in peace.” – T. Moore‬