It is possible to list binaries in BinaryFiles and thereby excluded them from R CMD check (although they are disallowed by CRAN). I am interested in the same functionality, but for object files. Background: in Rgraphviz, we (I) include pre-compiled object files for use on Windows, because generating these object files requires a full unix environment, and not just the pieces exposed in Rtools. I am interested in excluding these files from R CMD check's check of whether "stray" object files are included. I imagine this could be useful for other packages. Best, Kasper D Hansen