First, open the Item Details window. Click View Item Catalog (the Inventory Management section) in the sliding window on the left side of the screen or in the Start Page window.
The next window will open.
The All Items and Unassigned categories are two main categories in the categories' hierarchy.
If you want to create a new category for the
All
Items
main category, choose All
Items and click on the 
If
you want to create a subcategory for one of the existing categories, choose
the category where you want to add a subcategory and click the on
the
The next window will open.
In the Add Category window, type the category name you want (Boeing was chosen as an example) according to the Windows standard naming conventions.
Property Sets
Add Property Sets
When you create a new Category, you may add Property Sets for all the items that are (or will be) included in this category.
To
add Property Sets, click on the 
Enter the appropriate property set name (
e.g. Boeing Property Sets) in the text field and
click
Add New Property
Click Add New Property. The next window will open. Enter any Property Name (Weight is given as an example) or choose it from the drop-down list.
Check on the Default Property Set box to set this Property Set as default one, if necessary. Click OK to add the Property Name.
Click OK. A new Property Set will be added.
Link to Existing Property
Instead of adding a new property, you may link to the existing one. Click Link to Existing Property.
The next window will open.
Choose the property you want to add and click OK.
The next window will open. You can see that a new Property Set Name and its Properties have been added.
Click OK. A New Category has been added.
For additional information, click the following links: