# Use a Predefined Schema

> To use the retraining capability in AI Center, you need to use a set of fields based on the fields already extracted by the out-of-the-box pre-trained ML Packages offered by UiPath. This list of fields is called a schema.

To use the retraining capability in AI Center, you need to use a set of fields based on the fields already extracted by the out-of-the-box pre-trained ML Packages offered by UiPath. This list of fields is called a schema.

To make it easier to get started, we are providing below the schemas for the out-of-the-box ML Packages. These are `.zip` files that you can import into Document Manager just like you would import a dataset.

The schemas for the pre-trained ML Packages provided by UiPath are available at the links in the table below:

| **Pre-trained ML Package** | **Schema** |
| --- | --- |
| **Invoices** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_invoices.zip) |
| **InvoicesAustralia** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_invoices_au.zip) |
| **InvoicesIndia** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_invoices_india.zip) |
| **InvoicesJapan** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_invoices_japan.zip) |
| **InvoicesChina** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_invoices_china.zip) |
| **Receipts** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_receipts.zip) |
| **PurchaseOrders** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_purchase_orders.zip) |
| **UtilityBills** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_utility_bills.zip) |
| **IDCards** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_id_cards.zip) |
| **Passports** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_passports.zip) |
| **RemittanceAdvices** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_remittance_advices.zip) |
| **BillsOfLading** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_bills_of_lading.zip) |
| **W2** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_w2.zip) |
| **W9** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_w9.zip) |
| **4506T** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_4506t.zip) |
| **Acord125** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_acord125.zip) |
| **ACORD25** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_acord25.zip) |
| **ACORD131** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_acord131.zip) |
| **ACORD126** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_acord126.zip) |
| **ACORD140** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_acord140.zip) |
| **990** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_990.zip) |
| **I9** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_i9.zip) |
| **FM1003** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_fm1003.zip) |
| **1040** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_1040.zip) |
| **Checks** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_checks.zip) |
| **Bank Statements** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_bank_statements.zip) |
| **Financial statements** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_financial_statements.zip) |
| **Packing Lists** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_packing_lists.zip) |
| **Vehicle Titles** | [Click here to download](https://oob-schemas.s3.us-east-2.amazonaws.com/Public/schema_vehicle_titles.zip) |

After downloading a `.zip` file from the table above, you can [**import the schema**](document-manager-import-documents.md#schema-import) in Document Manager by clicking the **Import** button ![docs image](https://dev-assets.cms.uipath.com/assets/images/document-understanding/document-understanding-dm_import.svg-e584f15b.png) from the management bar, and then uploading the `.zip` file from the **Import data** dialog box. Document Manager detects that it is a new schema and imports it directly.