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

# Adding Fields to Structured Sheets

> Define fields in a structured sheet to extract consistent data from documents.

In a **structured sheet**, columns are defined as **fields** rather than open-ended questions. A field specifies a precise data point to extract from each document, and a structured, consistent value is returned for every row.

## Adding a field

1. Open a structured sheet in the sheet editor.
2. Click the **+ Add Field** button at the far right of the column header row (it is always pinned to the end of the table).
3. A new column appears with its header in edit mode. Type the field name and press **Enter** to confirm.

Field cells begin generating immediately for all documents currently in the sheet.

## Naming fields effectively

Field names act as the extraction instruction. Clear, specific names produce better results:

| Less effective | More effective            |
| -------------- | ------------------------- |
| Capacity       | Installed capacity (MW)   |
| Date           | Commercial operation date |
| Party          | Offtaker name             |
| Term           | PPA term (years)          |

## Renaming a field

Click a field's column header to enter edit mode. Update the name and press **Enter** or click away to save. Renaming a field triggers re-extraction for all cells in that column.

## Resizing columns

Drag the resize handle on the right edge of any field column header to adjust its width. This is useful when field values vary significantly in length.

## Processing states

Structured sheet cells follow the same processing states as document sheet cells:

| Indicator              | Status     |
| ---------------------- | ---------- |
| Clock icon             | Pending    |
| Spinning orange circle | Processing |
| Green checkmark        | Ready      |
| Red X                  | Error      |

## Row and column virtualization

Structured sheets use full virtualization — only the rows and columns visible on screen are rendered. This means sheets remain fast even with large numbers of documents and fields.

## Adding documents

See [Adding Documents and Questions](/sheets/adding-documents-and-questions) for instructions on adding documents to a structured sheet. The process is the same as for document sheets.