Text-to-speech synthesizers must process text, and therefore require some knowledge of text structure. While many TTS systems allow for user control by means of ad hoc 'escape sequences', there remains to date no adequate and generally agreed upon system-independent standard for marking up text for the purposes of synthesis. The present paper is a collaborative effort between two speech groups aimed at producing such a standard, in the form of an SGML-based markup language that we call STML-Spoken Text Markup Language. The primary purpose of this paper is not to present STML as a fait accompli, but rather to interest other TTS research groups to collaborate and contribute to the development of this standard.