Targets of opportunity can be proposed. The maximum time allocation per year for TOO's from all participants is 5% of the total time. TOO's will be approved by the national selection process and follow the same acceptance procedure as other observations. Upon notification of a TOO, the SXGCF will notify the the SXG project leader who will decide on the suitability of possible TOO's in consultation with the project scientist of each instrument. More than half the instrument PIs must agree to the suspension of the observing program for the TOO since other instrument observing programs will be interrupted to allow observation of the TOO.