Disciplinary notes, yellow cards, penalty points – can employees be disciplined that way?

Can employer use other tools than disciplinary penalties or is this the only possible tool? The question is whether the employer is entitled to discipline workers using tools that are not explicitly provided for in the Labour Code, such as disciplinary notes, “yellow cards” or “penalty points” – Karolina Kanclerz, Paweł Sych, and Łukasz Marzec comment for HR na Szpilkach magazine.

Article: here.