warn against save

[gdkrmr]

from a piece of code

save(foo, file = "data.Rdata")

....

load("data.Rdata")

it is absolutely not clear what variables are being loaded into the workspace.

something like:

saveRDS(...)
foo <-  readRDS(...)

is much cleaner. Maybe mention that the representation of R object may change between version of R and should therefore not be relied on for long term storage data or sending data to other people.