Cease and desist obligation

The (with penalty clause) cease and desist obligation seems to be the correct reaction on a justified warning.  With this declaration the party cautioned commits himself to desist from the behaviour that forms the object of the warning.  If there is already a violation, it is important that the written undertaking includes a contractual penalty i.e. a declaration with penalty clause.  Only by giving a cease and desist declaration with penalty clause can we prevent a preliminary injunction to being ordered.