The high-performance computing (HPC) I/O stack has been complex due to multiple software layers, the inter-dependencies among these layers, and the different performance tuning options for each layer. In this complex stack, the definition of an “I/O access pattern” has been re-appropriated to describe what an application is doing to write or read data from the perspective of different layers of the stack, often comprising a different set of features. It has become common having to redefine what is meant when discussing a pattern in every new study as no assumption can be made. This survey aims to propose a baseline taxonomy, harnessing the I/O community’s knowledge over the last 20 years. This definition can serve as a common ground for HPC I/O researchers and developers to apply known I/O tuning strategies and design new strategies for improving I/O performance. We seek to summarize and bring a consensus with the multiple ways to describe a pattern based on common features already used by the community over the years.