> ## 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.

# Parameter

> Provides access to parameter values.

`Parameter` represents a single transaction parameter — its name, value, and whether it can be modified.

## Properties

| Name           | Type   | Access level | Description                           |
| :------------- | :----- | :----------- | :------------------------------------ |
| **IsReadOnly** | bool   | Read-write   | `true` if the parameter is read-only. |
| **Name**       | string | Read-only    | The name of the parameter.            |
| **Value**      | string | Read-write   | The value of the parameter.           |

<Warning>
  Writing to a parameter whose `IsReadOnly` is `true` interrupts rule execution with an error.
</Warning>

## Related topics

* [Transaction](/vantage/documentation/skill-designer/document/rule-verification/transaction)
* [SkillParameter](/vantage/documentation/skill-designer/document/rule-verification/skill-parameter)
* [Object model](/vantage/documentation/skill-designer/document/rule-verification/object-model)