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A general description is here.
cat(x, file=) in Rgui tried to interpre UTF-8-encoded strings for the console rather than converting them to the native encoding.
help(try.all.packages = TRUE) is much faster (although the time taken by the OS to find all the packages the first time it is used can dominate the time).
pbeta(x, *, log.p = TRUE) is sometimes more accurate, e.g., for very small x.
o Unserializing a pre-2.8 workspace containing pure ASCII character objects with a LATIN1 or UTF-8 encoding would corrupt the CHARSXP cache.