[R] CRAN policies - citing others

Dear R users, we try to submit a package to CRAN. One of our function pbcOptim.R uses lbfgsb.cpp which is a slight modification of optim.c. In the documentation for pbcOptim.R we said The code for pbcOptim is based on that of \code{\link{optim}}. In particular, pbcOptim calls /src/lbfgsb.cpp

Re: [R] CRAN policies - citing others

I believe this is what you should do: * In the lbfgsb.cpp from base R, include the GPL blurb and R copyright holders. Also add your own names. (see e.g. https://github.com/hadley/pryr/blob/master/src/typename.cpp) * In the DESCRIPTION, add the R core team as a contributor,