June 9th, 2020
The Internationalization Working Group has published a First Public Working Draft of Rules for Simple Placement of Japanese Ruby. This document provides a simple set of rules for placement of Ruby text in Japanese typography that can be used as a minimum baseline for implementers and specification writers. It was developed by the JLReq (Japanese Layout) Task Force as a companion to Requirements for Japanese Text Layout 日本語組版処理の要件（日本語版）.
Ruby is the name given to the small annotations in Japanese content that are rendered alongside base text, usually to provide a pronunciation guide, but sometimes to provide other information.