The CCITT, considering that proper interworking of this telegraph transmission with the international telegraph services must be ensured; CCITT Recommendation F.10 concerning character error rate for telegraph communications, unanimously recommends that, for the coast-earth station-to-mobile terminal and mobile terminal-to-coast-earth station links, sufficient margin should be included to overcome adverse propagation conditions. The objective should be that propagation conditions should not contribute any character errors for at least 95% of all calls with mobile terminals within the satellite service area. With the exception of blockage effects, propagation conditions should not contribute more than 8 errors in 100 000 characters with a 99% confidence level for mobile terminals at the edge of the service area.