This section is from the "Version Control with Subversion" book, by Ben Collins-Sussman, Brian W. Fitzpatrick and C. Michael Pilato. Also available from Amazon: Version Control with Subversion.
Here ends the automated magic. Sooner or later, once you get the hang of branching and merging, you're going to have to ask Subversion to merge specific changes from one place to another. In order to do this, you're going to have to start passing more complicated arguments to svn merge. This next section describes the fully expanded syntax of the command and discusses a number of common scenarios that require it.