You can assign a category to a format during creation of a format (recommended) or any time later.
The reasons of assigning categories to formats are explained in Formats and categories.
Note: if you are already editing a format, then start with the step #3.
To assign a category to a format
1.Edit a format as explained in Edit formats in EdAdmin4.
2.In Category, select a category in the list. This will make the format visible only for article elements of the specified category.
To unassign a category from a format
1.Edit a format as explained in Edit formats in EdAdmin4.
2.In Category, select <Not Set>.
Note
You can assign to a format only one category.
Should you need to assign more categories to the same format, duplicate the format and assign the same style libraries to all the format copies.