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.
svn propdel — Remove a property from an item.
This removes properties from files, directories, or
revisions. The first form removes versioned properties in
your working copy, while the second removes unversioned
remote properties on a repository revision
(TARGET only determines which
repository to access).