> For the complete documentation index, see [llms.txt](https://docs.b2ihealthcare.com/snowray/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.b2ihealthcare.com/snowray/v2.9/reference/resources/codesystems/custom-code-systems/authoring.md).
# Authoring
The authoring process of Custom Code Systems can flow on two different levels: [schema](#schema) and [concept](#concept).
## Schema
New property definitions can be added to the Code System on the ***Schema*** tab, after clicking on the 
button in the middle area.
The following attributes can be specified for a property definition:
| Attribute | Description |
| ----------------- | ------------------------------------------------------------------------------------------------------------------------- |
| **Name** | Unique name of the property (mandatory) |
| **Type** | [Type ](/snowray/v2.9/reference/resources/codesystems/custom-code-systems.md#schema)of the property (mandatory) |
| **Cardinality** | Defines the [number of elements](/snowray/v2.9/reference/resources/codesystems/custom-code-systems.md#schema) (mandatory) |
| **Default value** | Initial value of the property |
| **Description** | Captures the purpose of the property |
{% hint style="info" %}
Once you added a property definition you can customize it by clicking in the text fields and entering an attribute value, or selecting one from the drop-down.
{% endhint %}
Changes to the property can be persisted by clicking the 
button.
{% hint style="info" %}
Different property types are indicated with different colors.
{% endhint %}
Existing properties can be edited after clicking the 
button.
## Concept
{% hint style="info" %}
To enter editing mode and access functionalities related to authoring, click on the button in the upper right corner of the selected Code System's content page.
{% endhint %}
New concepts can be added to the Code System on the ***Content*** tab, after clicking on the button.
{% hint style="info" %}
If you select a concept from the tree, it will be considered the parent concept. You can change this in the creation wizard.
{% endhint %}
| Field | Description |
| ---------- | ------------------------------------------------------------------------------------------------------------------------------- |
| **Term** | The name of the new concept (mandatory) |
| **Code** | The identifier of the new concept. If you leave this field empty, the system will automatically generate an ID for your Concept |
| **Parent** | The concept under which the new concept will be created |
After pressing the button, the new concept will be added to the Code System tree and its editor will automatically open on the right side.
The preferred term of the concept - by default, the one defined during creation - is indicated with an 
icon.
{% hint style="info" %}
You can specify alternative terms for a concept, and even move the preferred flag to the newly added terms.
{% endhint %}
## Properties
Property types defined in the Code System Schema are automatically displayed in the concept editor. Values can be added to the properties by pressing the button.
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If you specified a default value in the Schema, the property will automatically be populated with it when adding a new value.
{% endhint %}
{% hint style="warning" %}
If you restricted the potential number of values of a property, e.g. to`1..1`, the button won't appear and you won't be able to add more values to the given property.
{% endhint %}
## Issues
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To access issue management related options, press the  button.
{% endhint %}
Users can create issues related to specific Code System concepts using the *Raise an issue* context menu option, while existing issues can be viewed by selecting the *Show issues* action.
{% hint style="info" %}
Want to find out more about issues? Visit the [Issue management](/snowray/v2.9/reference/issue-management.md) page for more information.
{% endhint %}