The administrator can decide the maximum number of categories the advert can be submitted to.
In this tutorial, I'll explain how the Multi categories App works, how to set it and what you can do with it.
The logic behind this App is really simple. Once the MultiCategories App is enabled, users are able to select more than one category for each item (advert).
After installation of the plugin (App) you just need to enable it and set the number of additional categories users will be able to add adverts to.
All is set and now when users are submitting the adverts, they'll see a new button under categories select list. Clicking it will reveal a new select list with categories selection.
When a user clicks the button and selects another category, the new (additional) set of custom fields is being displayed. This way user is able to add as many categories as the limit set in the plugins (app) options.
Once the advert is published it's now being visible in all selected categories. The categories are listed in the Advert details section of the advert's page.
Of course, the site administrator can assign the adverts to more categories from the backend.
To do it: