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

# Document types

> Choose how to send a Box Sign request for unstructured documents, templates, or structured tagged files.

In your application, you sign different documents from many sources.
How can your application process these documents so the Box Sign service
recognizes them?

A signature request can have multiple requirements, or inputs, beyond the traditional signature, such as name, date, and initials. These inputs are called signature properties. The Box Sign service needs to know where to place these inputs in the document, and how to recognize them.

The first step is to consider if the document has the necessary information for the Box Sign service to recognize the signature properties. If not, then the [document is unstructured][unstructured-docs], and should be prepared before sending the signature request. This is called document preparation, and is an extra step automatically created by the Box Sign service.

There are two other types of documents that already have the necessary
information for the Box Sign service to recognize the signature properties.
These are [sign templates][sign-templates], managed in the Box application, and
[structured documents][sign-structured-docs], which are dynamically generated
documents that contain specific tags representing the signature properties.

<Next>Signing unstructured docs</Next>

[unstructured-docs]: /guides/box-sign/document-types/unstructured

[sign-templates]: /guides/box-sign/document-types/sign-templates

[sign-structured-docs]: /guides/box-sign/document-types/structured