> For the complete documentation index, see [llms.txt](https://karedi.gitbook.io/karedi/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://karedi.gitbook.io/karedi/next-level/txt-file-format/format-version.md).

# Format version

Standarized UltraStar format specification

Although all songfiles follow the basic txt format specified [here](/karedi/next-level/txt-file-format.md), due to a lack of a central authority, over the years some differences in the way new features were realized started to appear between various communities.

To avoid compatibility issues and enforce a common standard, format specification standarization project was started.

## What is UltraStar format specification?

For each format version, it specifies the set of available features as well as the set of rules that the txt files should follow. Mostly it defines which [tags ](/karedi/next-level/txt-file-format/tags.md)are available and what values can be used.

For more details see the official page:  <https://usdx.eu/format/#specs>

## Do I need to care about it?

Not necessarily, you can just choose the latest version (starting with `1.` e.g. `1.1.0`) to maximize available features and Karedi will make sure your songfile is compliant with it.

All software is supposed to ignore unknown tags, so even if some UltraStar-like game does not yet support the latest version, the song should still work as normal, just without the extra features.