Specifies the markup syntax used to format the Chat message text. Applies to the `text` field of the `Message` resource.

| Enums ||
|---|---|
| `MARKUP_SYNTAX_UNSPECIFIED` | Represents the unspecified value. |
| `MARKUP_SYNTAX_CHAT` | Uses Google Chat's markup syntax. See <https://developers.google.com/workspace/chat/format-messages#format-texts> for more information. |
| `MARKUP_SYNTAX_MARKDOWN` | Uses Markdown syntax. This syntax is based on the [CommonMark](https://commonmark.org/help/) specification, with additional extensions. See <https://developers.google.com/workspace/chat/format-messages#format-texts> for more information. |