Pretty sure pjmlp meant Functional Programming.

"Railway Oriented Programming" is a term coined by Scott Wlaschin, a prominent F# practitioner who popularized the term with helpful blog posts, slides, and speaking events.

Outside of the F# community (i.e. those that have not seen Wlaschin's materials) however, the term is rarely used. The larger FP community has more more general terms they use instead for the whole class of patterns surrounding this.

You are correct. I just thought the term was more widely known outside the F# world.

well it could be, I certainly don't speak for everyone; just haven't seen it personally myself yet.