Can Hubot send HTML or other formatted message to Hipchat?

Looking at the Hubot documentation there seems to be no way to send a formatted message to a Hipchat client from a Hubot script.

Does anyone know the best way to represent lines of text sent from Hubot?

Version 1 of the Hipchat API (although deprecated) suggests that a parameter message_format

can be used to specify an HTML message.

Many thanks.