This string sets a site-of-origin (SOO) value, as an absolute value or regular expression up to 32 bytes, to match against the SOO of a VPN route in this policy term; an unset attribute is zero length. An admin uses it to prevent VPN routing loops by matching routes based on which site originally injected them. For example, setting csRtPolicyTermFromVpnSoo to a specific SOO value lets this term match and reject routes re-advertised back toward the site that originated them.