The BLOCK(*YES) and BLOCK(*NO) keywords are accepted on file declarations in both free-format (DCL-F) and fixed-format (F-spec). BLOCK is a performance hint that controls whether records are read and written in groups rather than individually.
rpgc accepts the keyword without error but treats it as a no-op: the JVM's JDBC layer manages its own record buffering, so the hint has no effect on runtime behavior. Programs that specify BLOCK compile and run identically to programs that omit it.