As the code of conduct is referred to in your written statement of particulars of terms and conditions, you should either have received or have been advised how you can access a copy of the document. Ask for a copy now and make sure you are familiar with it.
To comply with the Acas Code of Practice on Disciplinary and Grievance Procedures, your employer should have its own written policies and procedures on how workplace issues are dealt with.
Your employer should make it clear, for example whether the code of conduct applies to behaviour outside of as well as during work hours, and what punishment is likely if the code is broken. Unless the rules are clear – and clearly communicated – the punishment may not be fair.