Reserved characters in SSML - Amazon Polly

Reserved characters in SSML

There are five predefined characters that can't normally be used within an SSML statement. These entities are reserved by the language specification. These characters are as follows:

Name

Character

Escape code

quotation mark (double quotation mark)

"

"

ampersand

&

&

apostrophe or single quotation mark

'

'

less than sign

<

&lt;

greater than sign

>

&gt;

Because SSML uses these characters as part of its code, to use these symbols in SSML, you must escape the character when you use it. You use the escape code instead of the actual character so it displays properly while still creating a valid SSML document. For example, the following sentence

We're using the lawyer at Peabody & Chambers, attorneys-at-law.

would be rendered in SSML as 

<speak>
We&apos;re using the lawyer at Peabody &amp; Chambers, attorneys-at-law.
</speak>

In this case, the special characters for the apostrophe and ampersand are escaped so the SSML document remains valid.

For the &, <, and > symbols, escape codes are always necessary when you use SSML. Additionallty, when you use the apostrophe/single quotation mark (') as an apostrophe, you must also use the escape code.

However, when you use the double quotation mark ("), or the apostrophe/single quotation mark (') as a quotation mark, then whether or not you use the escape code is dependent on context.

Double quotation marks

  • Must be escaped when in a attribute value delimited by double quotes. For example, in the following AWS CLI code 

    --text "Pete &quot;Maverick&quot; Mitchell"

  • Do not need to be escaped when in textual context. For example, in the following

    He said, "Turn right at the corner."

  • Do not need to be escaped when in a attribute value delimited by single quotes. For example, in the following AWS CLI code 

    --text 'Pete "Maverick" Mitchell'

Single quotation marks

  • Must be escaped when used as an apostrophe. For example, in the following 

    We&apos;ve got to leave quickly.

  • Do not need to be escaped when in textual context. For example, in the following

    "And then I said, 'Don't quote me.'"

  • Do not need to be escaped when in a code attribute delimited by double quotes. For example, in the following AWS CLI code 

    --text "Pete 'Maverick' Mitchell"