/ˈjɛləʊ dɒɡ ˈkɒntrækt/ – Phrase
Definition: Hợp đồng cấm công nhân tham gia hoạt động đoàn kết công đoàn.
A more thorough explanation: a historic type of US employment contract that prevented the employee from joining a trade union
Example: The yellow-dog contract was an anti-union device, used especially in the coal industry.