# Pronouncing acronyms and abbreviations
<a name="sub-tag"></a>

*<sub>*

This tag is supported by generative, long-form, neural, and standard TTS formats.

Use the `<sub>` tag with the `alias` attribute to substitute a different word (or pronunciation) for selected text such as an acronym or abbreviation.

This uses the syntax:

```
<sub alias="new word">abbreviation</sub>
```

 In the following example, the name "Mercury" is substituted for the element's chemical symbol to make the audio content clearer.

```
<speak>
     My favorite chemical element is <sub alias="Mercury">Hg</sub>, because it looks so shiny. 
</speak>
```