The Adventure Programming Language (APL) binary format is based on one-byte opcodes and space-efficient, variable size operands. Each non-comment line of the source code corresponds to one command-level opcode. Most operands of the command-level opcodes are numeric information that can be specified with an explicit number, a variable, or an expression. These operands are represented through a second level set of one-byte opcodes. For more information on operands, opcodes, and GetVar codes, see the topics Command Opcodes and Operands and Expressions and GetVar Codes.