Documentation for Subversion (sometimes referred to as "SVN") is available here.

Developer Subversion Access via SSH

Only project developers can access the SVN tree via this method. SSH must be installed on your client machine. Substitute developername with the proper values. Enter your site password when prompted.

svn checkout svn+ssh://developername@r-forge.r-project.org/svnroot/termstrc

Installation of Packages in R

If the package passed the quality check it can be installed directly via:

install.packages("packagename",repos="http://r-forge.r-project.org")