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

# AltoVersionEnum

AltoVersionEnum enumeration constants are used to denote format version of the exported ALTO file.

```
typedef enum {
 AV_Version_20,
 AV_Version_21,
 AV_Version_30,
 AV_Version_31,
 AV_Version_40,
 AV_Version_41,
 AV_Version_42
} AltoVersionEnum;
```

## Elements

| Name                | Description                                          |
| ------------------- | ---------------------------------------------------- |
| AV\\\_Version\\\_20 | The version of the exported ALTO file format is 2.0. |
| AV\\\_Version\\\_21 | The version of the exported ALTO file format is 2.1. |
| AV\\\_Version\\\_30 | The version of the exported ALTO file format is 3.0. |
| AV\\\_Version\\\_31 | The version of the exported ALTO file format is 3.1. |
| AV\\\_Version\\\_40 | The version of the exported ALTO file format is 4.0. |
| AV\\\_Version\\\_41 | The version of the exported ALTO file format is 4.1. |
| AV\\\_Version\\\_42 | The version of the exported ALTO file format is 4.2. |

## Used in

[IAltoExportParams::AltoVersion](/fine-reader/engine/api-reference/parameter-objects/export-parameters/altoexportparams#altoversion)