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.
svnlook uuid — Print the repository's UUID.
UUID
svnlook uuid REPOS_PATH
Print the UUID for the repository. the UUID is the repository's universal unique identifier. The Subversion client uses this identifier to differentiate between one repository and another.
$ svnlook uuid /var/svn/repos e7fe1b91-8cd5-0310-98dd-2f12e793c5e8