“There’s a lot of different terminology around open access, particularly around various levels of open access. I thought it might be helpful to aggregate some of the disparate information into one source on the TOPS Github, which is below! This is sourced from Open Book Publishers, Researcher.Life, and Taylor & Francis.There are many kinds of open access, but they broadly fit into three categories: libre, which is open access that allows content to be free to read and generally, there are no barriers for reuse, gratis, which is open access that allows content to be free to read, but has barriers for reuse, and then there’s one level (black) that fits into neither libre nor gratis….”
The debate about open access has until now focused on the gold (journals) versus the green route (manuscript self?archival).
Recently an even more disruptive form of OA has emerged, in the form of illegal article copies retrievable from academic social networks or pirate sites.
Illegal, or “black open access”, provides access to a large part of the pay?walled article output which cannot be found in repositories….”