Company rules, regulations and policies, if they are included in the contract of employment, may be legally binding but much will depend on the nature of a particular rule and whether it was the intention of the parties to make the rules part of the employment contract.
Employers are increasingly developing written policies and procedures to deal with workplace issues, particularly those that are of a sensitive nature, for example harassment or the misuse of company e-mail systems, and making it clear that breaches of these policies will be regarded as misconduct and subject to disciplinary action.