# Collection tree

In order to use browsing by tree, available in the *Catalog*, we need to configure the structure of said tree.

Organizing objects for their view in a tree pattern is associated to a metadata descriptor, which has to exist in the metadata schema of those objects we wish to see organized in a tree structure. The name of the metadata descriptor to use for the collection tree must be configured into a configuration variable named *“Metadata Descriptor used to classify object”*.

Every node configured in the tree has a value associated to it, which has to correspond (totally or partially) to the configured descriptor value for each object.

![](/files/-MjyXwqwGBF6hfHpewgg)

The value of the metadata descriptor associated to each and every node must be unique, thus avoiding duplicities in the classification of elements.

The edit form lets us make changes in the structuring of the nodes, by altering hierarchy, the descriptor’s description or value, and the addition and subtraction of elements.

{% hint style="info" %}
**NOTE**: regarding the suppression of elements, we need to keep in mind that the deletion is recursive; in other words, when one node is eliminated, all of its children nodes will be eliminated too.
{% endhint %}


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