> ## Documentation Index
> Fetch the complete documentation index at: https://docs.abbyy.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Skill parameters
> Configure and manage skill parameters to adjust skill behavior without retraining or republishing.
Skill parameters let you adjust the behavior of a skill without changing, retraining, and publishing it again — useful for complex skills that require large training sets.
* In a Document skill, parameters adjust the skill to different document-processing scenarios.
* In a Process skill, parameters reference and adjust the parameters of the Document skill it wraps.
Only users with the Tenant Administrator and Skill Designer roles can create and edit skill parameters.
## Use cases
### Processing invoices from different customers using their own data catalogs
Use the same built-in [Invoice skill](/vantage/documentation/skill-catalog/built-in-skills/invoice-skills/invoice-overview) to process invoices from multiple customers by passing a different data catalog in each Vantage API transaction. Some built-in skills, including the Invoice skill, ship with default parameters that point to data catalogs — you just supply a new catalog value per transaction.
For details, see [Access skill parameters via the Vantage API](/vantage/documentation/skill-designer/skill-parameters/accessing-skill-params).
### Restricting automatic country and expense type detection
Use the [Receipt skill](/vantage/documentation/skill-catalog/built-in-skills/receipt-skills/receipt) to process retail receipts from a single country — for example, Germany. Some built-in skills, including the Receipt skill, expose default parameters that restrict automatic country and expense type detection. To process only German retail receipts, set the parameter values to `DE` and `GeneralRetail`. The **Country** and **Expense Type** fields are redefined accordingly and documents process faster.
### Assigning a new value to a certain field
Configure a Document skill to assign a new value to the **Date** field for a specific document set. Create a Boolean skill parameter, set its default to **No**, and add a scripted rule for the **Date** field:
```javascript theme={null}
if (Context.Skill.Parameters["New parameter"].Value == false) {
Context.GetField("Date field").Value = 'New date'
}
```
When the parameter is **No** for a given document set, the rule runs and the `New date` value is assigned to the **Date** field.
## Relations between parameters on different levels
A Process skill can include an Extract activity, which in turn uses a Document skill. Each level of this nested structure has its own parameters:
* **Document skill parameters** — share extracted data between activities of the Document skill and specify document-processing settings. Viewable and editable in Vantage, Advanced Designer, and via the Vantage API.
* **Extract activity parameters** — essentially the Document skill's parameters as accessed from the Extract activity. Viewable and editable in Vantage.
* **Process skill parameters** — reference Extract activity parameters and can override their values. Viewable and editable in Vantage and via the Vantage API.
If your Document skill has no parameters, you don't need to add any to the Process skill.
## Types of skill parameters
Skill parameters can be one of three types:
| Type | Description |
| :--------------- | :----------------------------------------------------------- |
| **Data Catalog** | Connection string to a data catalog on the connected server. |
| **Text** | String value. |
| **Boolean** | Boolean value — the possible values are **Yes** and **No**. |
## Related topics
Configure parameters on a Document skill for different processing scenarios.
Access and modify Document skill parameters from a Process skill.
Use the Vantage API to set and read parameter values per transaction.
Automate field validation with scripted business rules.
Built-in skill that ships with default parameters for receipt processing.
Built-in invoice skills that ship with default parameters.