> ## Documentation Index
> Fetch the complete documentation index at: https://docs.gobl.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Attribute

Attribute describes a named feature or property of the parent object, such as the color or size of an item.

## Schema ID

`https://gobl.org/draft-0/org/attribute`

## Properties

| Title  | Property | Type                              | Description                                                                                                                                       |
| ------ | -------- | --------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------- |
| Label  | `label`  | string                            | Label for the attribute, used for presentation in converted outputs such as PDFs.                                                                 |
| Key    | `key`    | [cbc.Key](/draft-0/cbc/key)       | Key that identifies the attribute, either from the list pre-defined by GOBL or an alternative agreed upon between the supplier and customer.      |
| Type   | `type`   | [cbc.Code](/draft-0/cbc/code)     | Type defines a code used to identify the attribute when the "key" field is empty, from a code list agreed upon between the supplier and customer. |
| Text   | `text`   | string                            | Text value of the attribute.                                                                                                                      |
| Code   | `code`   | [cbc.Code](/draft-0/cbc/code)     | Code value of the attribute, used as an alternative to text when the value comes from a code list agreed upon between the supplier and customer.  |
| Amount | `amount` | [num.Amount](/draft-0/num/amount) | Amount used when the attribute represents a numeric or measurable value.                                                                          |
| Unit   | `unit`   | [org.Unit](/draft-0/org/unit)     | Unit of measure that accompanies the amount.                                                                                                      |
| Date   | `date`   | [cal.Date](/draft-0/cal/date)     | Date value of the attribute.                                                                                                                      |

## Key Values

| Value                     | Description                                                                                                           |
| ------------------------- | --------------------------------------------------------------------------------------------------------------------- |
| `color`                   | Color of the item, either as a name or a code such as RAL or Pantone.                                                 |
| `size`                    | Size of the item, such as a clothing size.                                                                            |
| `material`                | Main material the item is made of, such as cotton or steel.                                                           |
| `length`                  | Length of the item itself, excluding packaging, usually as an amount with a unit of measure.                          |
| `width`                   | Width of the item itself, excluding packaging, usually as an amount with a unit of measure.                           |
| `height`                  | Height of the item itself, excluding packaging, usually as an amount with a unit of measure.                          |
| `diameter`                | Diameter of the item itself, excluding packaging, usually as an amount with a unit of measure.                        |
| `weight`                  | Weight of a single unit of the item itself, excluding packaging, usually as an amount with a unit of measure.         |
| `volume`                  | Volume of a single unit of the item itself, excluding packaging, usually as an amount with a unit of measure.         |
| `production`              | Date the item was produced or manufactured.                                                                           |
| `expiry`                  | Date the item expires or is best consumed before.                                                                     |
| `nutrition+energy`        | Energy content per 100g or 100ml, usually in kilojoules (kj) or kilocalories (kcal).                                  |
| `nutrition+fat`           | Total fat content per 100g or 100ml, usually in grams.                                                                |
| `nutrition+saturated-fat` | Saturated fat content per 100g or 100ml, usually in grams.                                                            |
| `nutrition+carbohydrates` | Carbohydrate content per 100g or 100ml, usually in grams.                                                             |
| `nutrition+sugars`        | Sugar content per 100g or 100ml, usually in grams.                                                                    |
| `nutrition+protein`       | Protein content per 100g or 100ml, usually in grams.                                                                  |
| `nutrition+salt`          | Salt content per 100g or 100ml, usually in grams.                                                                     |
| `nutrition+fibre`         | Fibre content per 100g or 100ml, usually in grams.                                                                    |
| `emissions+co2e`          | Greenhouse gas emissions of a single unit of the item expressed as a carbon dioxide equivalent, usually in kilograms. |

## Validation Rules

| Field                    | Test                                                                                                                                           | Validation Code / Message                                                                              |
| ------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------ |
| <small>Attribute</small> | <ul class="gobl-test"><li>(string(Key) == "") != (string(Type) == "")</li></ul>                                                                | `GOBL-ORG-ATTRIBUTE-01`<br />Attribute must have either a key or a type, but not both                  |
| <small>Attribute</small> | <ul class="gobl-test"><li>(Text == "" ? 0 : 1) + (string(Code) == "" ? 0 : 1) + (Amount == nil ? 0 : 1) + (Date == nil ? 0 : 1) == 1</li></ul> | `GOBL-ORG-ATTRIBUTE-02`<br />Attribute must have exactly one of the text, code, amount, or date values |
| <small>Attribute</small> | <ul class="gobl-test"><li>String(Unit) != ""</li><li>Amount != nil</li></ul>                                                                   | `GOBL-ORG-ATTRIBUTE-03`<br />Attribute unit may only be used alongside an amount                       |