As you surely noticed ItemsAdder uses namespaces to identify most of the things it manages. A namespace is a group of elements, in this case a group of items/blocks/mobs... With namespaces you can easily understand where a particular item, sound, block.. comes from.


All realcraft items are under the realcraft namespace, so when you use the /iaget command you can see all items IDs start with realcraft:

How can I define my own namespace?

Now that you see how it works you want to ask me this question: How can I create my own namespace?
In order to keep everything organized you have to create your own namespace. First step is to create a subfolder inside: plugins\ItemsAdder\contents\
In this example namespace will be myitems so create a folder named like the namespace: contents\myitems\
Open the myitems folder and create a new file, you can call it like as prefer, I named it myswords.yml. contents\myitems\myswords.yml
Open the new .yml file and paste this:
namespace: myitems
As you see I set namespace to myitems, which is the namespace I chose before and it's the same name of the folder. Remember to change it based on your namespace.
You can create as many namespaces you want! This allows you to easly organize your packs of items.
You can create as many as .yml files you want in the same namespace! This allows you to organize items/things types better. For example I divided my items in swords, blocks, food, drinks...
All this "nesting" could seem boring but trust me, it reduces errors as much as possible and allows you to find everything easily.