> 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/voicexml/tags/lexicon-tag.md).

# \<lexicon>

## \<lexicon> <a href="#lexicon" id="lexicon"></a>

Specifies a pronunciation lexicon for the prompt. This tag is only supported with the RealSpeak TTS engine.

### Attributes

<table><thead><tr><th width="164.33333333333331">Name</th><th width="164">Data type<select><option value="c2fde36fff8a4e1297e414f03bb6cd1a" label="String" color="blue"></option><option value="bbfacf4ecbb74f5fa339105000de2ccb" label="Integer" color="blue"></option><option value="69c199f2193d449b8a9b6bb4b15aa501" label="Boolean" color="blue"></option></select></th><th>Description</th></tr></thead><tbody><tr><td>uri</td><td><span data-option="c2fde36fff8a4e1297e414f03bb6cd1a">String</span></td><td>The URI specifying the location of the dictionary file.</td></tr><tr><td>type</td><td></td><td>not supported</td></tr></tbody></table>

### Notes

The dictionary file must always contain a SubHeader section that defines the contents of a Data section. These contents can either be expansions or pronunciations.

In the example below, the first SubHeader and Data blocks define expansions, while the second Subheader And Data blocks define pronunciations.

For pronunciations, you should follow the guidelines to the Phoneme Set for Nuance RealSpeak here: [TTS Engine Characteristics](/dev/developer-reference/tts-engine-characteristics.md). Please note that your web servers must be configured to associate the .dct extension with a mime-type of application/edct-text-dictionary.

### Example

**lexicon.vxml**

```markup
<?xml version="1.0"?>
<vxml version="2.0">
    <form>
        <block>
            <prompt>
                <lexicon uri="http://path/to/the/lexicon.dct"/>
                The doc diagnosed the pt with muscae volitantes.
            </prompt>
        </block>
    </form>
</vxml>
```

**lexicon.dct**

```
[Header]
Language = ENU

[SubHeader]
Content=EDCT_CONTENT_ORTHOGRAPHIC
Representation=EDCT_REPR_WSZ_STRING

[Data]
doc     Doctor
pt      Patient

[SubHeader]
Content = EDCT_CONTENT_BROAD_NARROWS
Representation = EDCT_REPR_SZZ_STRING

[Data]
muscae  //'m^sk^
volitantes      //'vAl.^.t@nz
```

> Computer: The doctor diagnosed the patient with muscae volitantes.

### Child Tags

None

### Parent Tags

[\<grammar>](/dev/voicexml/tags/grammar-tag.md), [\<prompt>](/dev/voicexml/tags/prompt-tag.md)


---

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```
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