---
title: Well-known types
framework: quicktime-file-format
role: article
role_heading: Article
path: quicktime-file-format/well-known_types
---

# Well-known types

Basic data types.

## Overview

Overview  |  |   |  |   |  |   |  |   |  |   |  |   |  |   |  |   |  |   |  |   |  |   |  |   |  |   |  |   |  |   |  |   |  |   |  |   |  |   |  |   |  |   |  |   |  |   |  |   |  |   |  |   |  |  The sorting variant of text is used for languages in which sorting is not evident from the written form (for example, some forms of Asian languages). In these cases, the sorting can only be performed by a human who can identify the actual words by understanding the context. For these languages, an alternative form of the same information can be stored using a different representation of the same text which can be machine sorted. This alternative representation is still sorted according to the sort rules of the language in question, as defined for the text system in use (for example, Unicode). In general, a simple lexical sorting which compares the values of the characters alone is not sufficient.

## See Also

### Types and usage

- [Extensibility](quicktime-file-format/extensibility.md)
- [Localization list sets](quicktime-file-format/localization_list_sets.md)
- [Type indicator](quicktime-file-format/type_indicator.md)
- [Locale indicator](quicktime-file-format/locale_indicator.md)
- [Data ordering](quicktime-file-format/data_ordering.md)
- [Location metadata](quicktime-file-format/location_metadata.md)
- [QuickTime metadata keys](quicktime-file-format/quicktime_metadata_keys.md)
- [Direction definition](quicktime-file-format/direction_definition.md)
- [Metadata handling](quicktime-file-format/appendix_d_metadata_handling.md)