href Attribute
Specifies a Uniform Resource Identifier (URI) that refers to prompt output markup or audio resource file.
<content href = "uri" >
Example
The following code demonstrates the use of the href attribute.
<prompt>
<content href="/VoiceMailWelcome.ssml" type="application/ssml+xml" />
After the beep, please record your message:
<content href="/wav/beep.wav" />.
</prompt>