[R] reserved words documentation

[white.denis@epamail.epa.gov]

I wanted a data frame component to be named "next", for example:

> m <- data.frame (matrix (0, nrow=2, ncol=2))
> names (m) <- c("prev", "next")
> m
  prev next
1    0    0
2    0    0

But "next" being reserved prevents $ indexing without quotes:

> m$next
Error: syntax error
> m$"next"
[1] 0 0

Although they are mostly obvious, I can't find in the documentation
(using Jon Baron's searcher, at least) a list of these words.  Am I
missing the documentation, or could such a list be added to a future
release?

thanks,
Denis