"As codified" by who?
Grammar text books.
And who wrote those?
Professors.
And who/what gives them the authority to decide which is the "proper" dialect of a language?
People tweeting stuff. We allow tweets from anyone.
RULES:
"As codified" by who?
Grammar text books.
And who wrote those?
Professors.
And who/what gives them the authority to decide which is the "proper" dialect of a language?