Adding a Category
To create a categories for your Gallery, enter a keyword (that correlates to the tag you set in ArcGIS Online or Portal for ArcGIS) and click Add. The new category should be added to the list of categories and will appear in the Categories panel of the Gallery page.
Editing / deleting a Category
To edit an existing category, click on the textbox you wish to edit within the Category list. Edit the category name and click Save at the bottom on the left main menuEdits will be automatically saved when you click elsewhere on the page. A green message box will then also appear in the bottom right indicating your Data updated. To delete a category, click the Red delete button next click Delete next to a category. As with editing, a 
Again, a green confirmation box will appear.
Ordering Category List
To reorder the categories list, click the dotted icon to the left of the category name. You can then drag and drop the category to another position in the list.
