The delete option allows you remove an entire category. You can choose to either delete the category and its contents or move the Post Icons to another category before deleting the selected category.
To move the Post Icons in the selected category ensure that the 'Delete all Post Icons from this category?' option is set to
No. Then from the drop down menu select the category that the Post Icons should be moved to. Then click the 'Delete' button. If you do not wish to keep the Post Icons that are included in the selected category set the 'Delete all Post Icons from this category?' option to
Yes.