> For the complete documentation index, see [llms.txt](https://docs.tonic.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.tonic.ai/textual/dataset-configure-redaction/textual-datasets-synthesis-options/synthesis-options-for-specific-entity-types/configure-phone-synthesis.md).
# Telephone number synthesis options
For Phone Number values, you can choose whether to generate a realistic phone number. If you do, then the generated values can be consistent with values generated in Structural.
Synthesis options for telephone number values
## Selecting the generator type
From the **Phone number generator type** dropdown list:
* To replace each phone number with a randomly generated number, select **Random Number**.
* To generate a realistic telephone number, select **US Phone Number**.\
\
The **US Phone Number** option generates values similar to those generated by the [Phone generator in Structural](/app/generation/generators/generator-reference/phone.md).
If you also configured a Textual statistics seed that matches a Structural statistics seed, then the synthesized values are consistent with values generated in Structural. A given source telephone number produces the same output telephone number in both applications.
For example, in both Textual and Structural, 123-456-6789 might be replaced with 154-567-8901.
## Replacing invalid telephone numbers
The **Replace invalid numbers with valid numbers** checkbox determines how Textual handles invalid telephone numbers in the data.
To replace the invalid with valid telephone numbers, check the checkbox.
If you do not check the checkbox, then Textual randomly replaces the numeric characters.
## Preserving the area code
The **Preserve US area code** checkbox determines whether Textual preserves the area code for telephone numbers in the United States.
To preserve the area codes from the source values in the output values, check the checkbox.
If you do not check the checkbox, then Textual replaces the entire telephone number, including the area code.
---
# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.
## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.
Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:
```
GET https://docs.tonic.ai/textual/dataset-configure-redaction/textual-datasets-synthesis-options/synthesis-options-for-specific-entity-types/configure-phone-synthesis.md?ask=&goal=
```
`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.
