Why do I get the "Invalid command 'AuthLDAPAuthoritative'" error when I try to set LDAP for SVN users?

The invalid command AuthLDAPAuthoritative error may occur if you need to upgrade Apache from version 2.0 to 2.2.

CollabNet Subversion 1.5 is bundled with the latest version of Apache (currently 2.2.x). It includes the module mod_authnz_ldap and does not include mod_auth_ldap. Hence compatibility issues arise due to missing directives. Upgrade your Apache version to 2.2 if you get the following error when trying to install CollabNet SVN:
 bash-3.00# /etc/init.d/collabnet_subversion start
    Starting CollabNet Subversion:
    Syntax error on line 29 of 
    Invalid command 'AuthLDAPAuthoritative', 
        perhaps misspelled or defined by a module not included in the server configuration