BlockSolve uses message numbers beginning at 10,000. It uses a significant but variable number of messages after that. Currently the number of messages used is 20+(10000*number_of_processors). The number of messages needed by BlockSolve depends on the problem being solved, but if the number of messages allocated to it is too small, then it will detect an error and return accordingly (if DEBUG_ALLis on). The current setting of 10,000 is very generous. The message numbers as well as the number of messages can be changed by altering BSprivate.h. This modification is a very simple task that any user can do. We hope to make the assignment of message numbers and avoidance of conflicts in the use of message numbers automatic as soon as this facility is provided by the Chameleon package.