A lot of packages in R (and I'm assuming in other languages as well) are licesed as "License: GPL-2 | GPL-3". Others as "GPL (>= 2)" and others as "MIT + file LICENSE". What does the "|" operator exactly mean?
If e.g. in a setting someone wants to avoid GPL-2 licenses explicitly, is a software-component (like an R package) licensed under "GPL-2 | GPL-3" still fine to use or does that always depend on GPL-2 as well?
Any sources appreciate