# OP\_CODESEPARATOR: Selective Script Signing

<figure><img src="/files/NrKSAsLMyOqh5RSuzR95" alt=""><figcaption></figcaption></figure>

OP\_CODESEPARATOR controls **which portions of a script** are included when creating and verifying signatures.

| Opcode            | Input   | Output  | Description                                                                                                                            |
| ----------------- | ------- | ------- | -------------------------------------------------------------------------------------------------------------------------------------- |
| OP\_CODESEPARATOR | Nothing | Nothing | Marks a boundary in the script. Signature verification operations only consider script content after the most recent OP\_CODESEPARATOR |

#### OP\_CODESEPARATOR Example: Witnessed Contract

**scriptSig:**

```
<witness_signature> <witness_public_key> <witness_name> <signatory_signature>
```

**scriptPubKey:**

```
OP_CODESEPARATOR
<contract_hash> OP_DROP
<signatory_public_key> OP_CHECKSIGVERIFY
OP_CODESEPARATOR
<witness_statement> OP_2DROP
OP_CHECKSIG
```

This pattern allows the witness to attest to the signing party's identity **without seeing the full contract content**. The witness signs only the witness statement, not the contract hash.


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