> For the complete documentation index, see [llms.txt](https://docs.plumvoice.com/dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.plumvoice.com/dev/developer-reference/tts-engine-characteristics.md).

# TTS Engine Characteristics

The Voice tag supports the following attributes, although not every TTS engine supports every attribute:

* \<gender>
* \<age>
* \<name>
* \<speak>
* \<voice>
* \<xml:lang>
* \<break>
* \<paragraph>
* \<phoneme>
* \<prosody>
* \<say-as>
* \<sentence>

Each TTS engine has a dedicated page that describes which attributes it supports and how to use them.

* [Amazon Polly](/dev/developer-reference/tts-engine-characteristics/amazon-polly-tts-engine/polly-voice-tag-attribute-details.md)
* [AT\&T Natural Voices](/dev/developer-reference/tts-engine-characteristics/at-and-t-natural-voices.md)
* [Cepstral Engine](/dev/developer-reference/tts-engine-characteristics/cepstral-engine.md)
* [RealSpeak Engine](/dev/developer-reference/tts-engine-characteristics/realspeak-engine.md)
* [Vocalizer 7](/dev/developer-reference/tts-engine-characteristics/vocalizer-7.md) (Beta\*)

{% hint style="info" %}
**\* Trying our beta features?**

Please share your feedback with us via email at **<beta@plumgroup.com>**.
{% endhint %}