What is `simp only []`

Stream: new members

[Vaibhav Karve]

What is the list of reductions used by simp only []? I could not figure it out from the mathlib API documentation at
https://leanprover-community.github.io/mathlib_docs/tactics.html#simp

[Mario Carneiro]

Nothing with a name, but it will perform beta reduction and constructor injectivity