# Specification

Use the specification section to learn how to work with the DIDWW API. Choose a topic to understand how to sort data,
paginate results, filter resources, include related data, set headers, manage relationships, or handle errors.

Important

All API request text is case-sensitive. Do not include spaces or white-space characters in parameter names or values.

**Sorting**

Learn how to sort API results by one or more fields, use relationship attributes, and apply ascending or descending
order.

[Sorting](sorting.html)

**Pagination**

Learn how to use page size and page number parameters to navigate large datasets and retrieve results efficiently.

[Pagination](pagination.html)

**Filtering**

Learn how to filter API results using single or multiple conditions, including arrays, to create precise and complex
queries.

[Filters](filtering.html)

**Sparse Fieldsets**

Learn how to request a partial response by selecting specific attributes with the `fields` parameter to avoid
over-fetching.

[Sparse Fieldsets](sparse-fieldsets.html)

**Inclusion of Related Resources**

Learn how to use the include parameter to retrieve related resources in a single API request and reduce multiple
queries.

[Inclusion of Related Resources](includes.html)

**Headers**

Learn about required API headers, including Content-Type, Accept, and authentication headers, for valid requests and
responses.

[Headers](headers.html)

**Relationships**

Learn how to manage resource relationships using `PATCH` to assign, update, or remove.

[Assigning Related Resources](relationships.html)

**Error Objects**

Learn about JSONAPI error objects, including structure, attributes, and common error types.

[Error Objects](errors/index.html)