---
title: "Filename Extensions"
description: "A filename extension is a suffix separated from the base filename by a period. It is applied to the name of a computer file to indicate the encoding (file format) of its contents."
canonical: "https://helpcenter.veeam.com/docs/styleguide/tw/extensions.html"
breadcrumb: "Style Guide > Tips and Tricks > Filename Extensions"
dateModified: "2026-09-03"
---

# Filename Extensions

A filename extension is a suffix separated from the base filename by a period. It is applied to the name of a computer file to indicate the encoding (file format) of its contents.

In Veeam technical documentation, we write filename extensions in upper-case letters following a period — non-italic, non-bold and non-underlined.

::: important

This applies only to filename extensions. When talking about a format, use just upper-case letters with no period.

:::

### Examples

1. The reverse incremental backup method produces a backup chain that consists of the last full backup [file (.VBK]{.mdhl-correct}) and a set of reverse incremental backup [files (.VRB]{.mdhl-correct}) preceding it.
2. On the **Output File** tab, specify a path to the resulting [.DOCX file]{.mdhl-correct}.
3. Now you can run the [.CMD file]{.mdhl-correct} to generate your project in the [DOCX format]{.mdhl-correct}.