I have received an official warning
If your employer thinks you are behaving inappropriately, he can give you an official written warning. This will be included in your personnel file and can play a role in a possible suspension or application for dismissal. Do you disagree with the warning? In that case, always file a written objection. If your employer does not withdraw the warning, your objection will in any case be placed in your file; this way you can demonstrate that you do not agree with it.