This chapter explains the impact of ongoing changes on subtitling for deaf and hard of hearing audiences (SDH) is manifold. It provides an overview of the conceptual frameworks and the terminology used in this field of professional practice and scholarly enquiry, and surveys a range of applications and norms in SHD. Manipulating the content to promote readability, understanding and enjoyment is the crux of ongoing research, and an important element in the very definition of quality in SDH. Achieving 'quality' appears to be the central aim of the now established providers of accessible content, who have contributed towards normalization by writing published and/or in-house standards and guidelines. The contexts where accessibility services have become mainstream are those in which stakeholders—legislators, providers, producers, distributers and end-users—have combined efforts to support and effect change. The chapter gauges the potential to challenge conventions, beliefs, and practices.