[R] Linking in R package documentation

[Rebecca Sela]

I have two straightforward questions about linking in the man pages for R packages:

First, is it possible to link from within parts of the documentation that are not the \seealso section?  For example, I would like to have something like:
\arguments{
  \item{correlation}{an optional \code{corStruct} object describing the within-group correlation structure; the available classes are given in \link{\code{corClasses}}}
}
When the package is compiled, the word corClasses is blue and underlines, but nothing happens when you click on it.  

Second, how do I link to a function of the same name in another package?  I thought I could use something like:
\seealso{\code{\link[nlme]{ranef}}}
but that gives a Page Not Found.  

Thank you in advance!

Rebecca