In Publication rules by category settings, can be defined for which categories the publication should be running – the publication can only run for entities that are allowed (checked) y the category. If the source publishing entity is of the item type, the allowed categories are checked hierarchically – the category on the item is checked first and then the category of the attached file is checked. Therefore, if the item contains, for example, several drawings (production, assembly,…) this setting can be used to specify where and how is to be published (for example, only one drawing).