So far, we have ignored the existing views and declared completely new ones. While this is didactically sensible, you'll rarely be in situations in which you want to define a new view for an existing model. Instead, you'll want to slightly modify the existing views, be it to simply have them show a field you added to the model in your addon, or to customize them according to your needs or your customers' needs.
In this recipe, we'll change the default partner form to show the record's last modification date and also make the mobile field searchable by modifying the search view. Then, we'll change the position of one column in the partners' list view.