and 
tabs, see [Customise the file-list columns](/how-to-guides/review/customize-file-list-columns.md).
{% endhint %}
The Document Index is a table. You choose which columns appear from the columns button in the toolbar above the index, which opens a panel headed **Customize Columns**. The **Description of Document** column is always shown and cannot be removed; every other column can be switched on or off. Columns always appear in a fixed order — switching a column on adds it in its standard position, and that order cannot be changed. By default a new Document Index shows **S/No.**, **Date**, **Description of Document**, **Vol**, and **Page**.
**These settings are saved per collection.** Which columns are shown, and each column's heading, width and alignment, are saved automatically with the collection you are working in, and everyone who opens that collection's Document Index sees the same columns. Each collection keeps its own: switch to another collection and you see that collection's columns.
## Available columns
| Column | Default heading | Contents |
| ------------- | ----------------------- | ------------------------------------------------ |
| Serial number | S/No. | The running serial number of the document. |
| File name | File Name | The document's file name. |
| Date | Date | The document date. |
| Description | Description of Document | The document description. |
| LOD reference | LOD Ref | A reference code carried over from a source LOD. |
| AB reference | AB Ref | A secondary (agreed bundle) reference code. |
| Volume | Vol | The bundle volume the document falls in. |
| Page | Page | The document's page reference within the bundle. |
## Per-column settings
The **Customize Columns** panel controls which columns appear, and lets you rename one — click the pencil button beside a column in the list. The width and alignment settings are not in that panel. To reach those, hover over a column heading in the Document Index itself: a rename icon appears at the right of the heading. Click it to open the **Column Settings** popup for that column.
| Setting | Where to set it | Description |
| ---------------- | ---------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Header label | The **Column Settings** popup, or the pencil button in **Customize Columns** | Override the default column heading. A heading typed in the **Column Settings** popup is limited to 40 characters; the rename box in **Customize Columns** does not enforce that limit. |
| Column Width (%) | The **Column Settings** popup, or by dragging | Set the column width as a percentage of the table, from 5% to 60%. This setting is not available for the **Description of Document** column, which always fills the remaining width automatically. |
| Alignment | The **Column Settings** popup | Align the column content left, center, or right. |
To set a width by dragging, drag the edge of the column heading that faces the **Description of Document** column — the right edge for columns to its left, the left edge for columns to its right. Dragging keeps to the same 5%–60% range. The **Description of Document** column cannot be dragged.
The **Column Settings** popup on the **S/No.** column also carries **Custom Initial** and **Initial Serial Number**, and the popup on the **Date** column carries the **Date Format Preset**. These apply to the whole index, not to that column alone.
Applying an index preset replaces the per-column settings above for every column — see [Document Index presets](/reference/index-presets.md).
These settings shape the Document Index on screen and in the Word and PDF index you export. The Excel **Document Index** export always uses its own fixed set of columns and headings — see [Export formats and options](/reference/export-formats-and-options.md).
## Related
| Serial numbers and date formats | Serial numbering options, date format presets, and sort order for the Document Index. | Serial numbers and date formats |
| Export formats and options | Output formats and the settings for exporting the Document Index. | Export formats and options |