Opcode number: 133
Short description: Fail the script unconditionally, does not even need to be executed.
OP_OR is a disabled opcode in the bitcoin scripting system.
OP_OR was intended to perform a bitwise OR operation on the top two items on the stack. This operation would take two numbers and produce a new number. In this result, each bit is the logical OR of the corresponding bits in the input numbers.
However, as part of a broader effort to reduce potential vulnerabilities and to simplify bitcoin's scripting language,
OP_OR was disabled early in bitcoin's history along with several other opcodes.
OP_OR is disabled, any script that includes it will result in the transaction being declared invalid, irrespective of the script's overall context.