Generic text summarization approaches often fail to address the specific
intent and needs of individual users. Recently, scholarly attention has turned
to the development of summarization methods that are more closely tailored and
controlled to align with specific objectives and user needs. While a growing
corpus of research is devoted towards a more controllable summarization, there
is no comprehensive survey available that thoroughly explores the diverse
controllable aspects or attributes employed in this context, delves into the
associated challenges, and investigates the existing solutions. In this survey,
we formalize the Controllable Text Summarization (CTS) task, categorize
controllable aspects according to their shared characteristics and objectives,
and present a thorough examination of existing methods and datasets within each
category. Moreover, based on our findings, we uncover limitations and research
gaps, while also delving into potential solutions and future directions for
CTS.Comment: 19 pages, 1 figur