# Choosing Your Scan ID

> Learn how to choose a scan ID that fits your organization's needs while adhering to Copyleaks' requirements.

A **Scan ID** is a unique identifier that you assign to every scan submitted to Copyleaks. This ID acts as a crucial link between your system and ours, allowing you to manage, track, and organize your scans effectively.

Choosing a thoughtful and consistent naming convention for your Scan IDs is essential for leveraging advanced Copyleaks features, such as preventing self-plagiarism and managing large volumes of scans.

## Core Requirements

While you have the flexibility to choose a Scan ID that aligns with your internal system, there are a few limitations to keep in mind:

-   **Character Length**: Must be between 3 and 36 characters.
-   **Allowed Characters**: The Scan ID can include lower case characters `a-z`, digits `0-9` and special symbols `!@$&-=_()';:., ~`. We recommend using lower case letters, digits and dashes for simplicity.

<Warning title="Unsupported Characters">
Uppercase letters (`A-Z`) and any characters not listed above are not permitted. If your internal IDs use unsupported characters, see the section on [Handling ID Mismatches](#handling-id-mismatches).
</Warning>

## Strategies for Naming Your Scan ID

The best approach is to create a structured Scan ID that embeds useful information. This allows you to easily identify a scan based on its scan ID and use advanced features like include or exclude specific groups of documents from a scan.

### Recommended Structure

A highly effective structure is:
`<ORGANIZATION_ID>-<AUTHOR_ID>-<DOCUMENT_ID>`

#### Examples
-   `tech-corp-employee456-q3-report`
-   `acme-university-student123-final-thesis`

<Note>
In plagiarism scans, this structure enables powerful filtering capabilities:
-   **Exclude by author**: Use a pattern like `*-student123-*` to prevent a student's new submission from being checked against their previous work.
-   **Include by organization**: Use `acme-university-*` to compare a document only against others from the same institution.
-   **Focus on document types**: Use `*-final-thesis` to analyze all final theses submitted.

For more information, see the [Prevent Self-Plagiarism](/concepts/features/self-plagiarism/) guide.
</Note>

## Handling ID Mismatches

If your internal system uses IDs that don't meet Copyleaks' requirements (e.g., they are too long or contain uppercase letters), the recommended solution is to generate a compliant Scan ID and maintain a mapping table on your end.

This table will link your internal entity ID to the corresponding Copyleaks Scan ID, ensuring seamless integration.

| Your Internal ID | Copyleaks Scan ID |
| :--- | :--- |
| `USER-9876-DOC-A` | `user9876-doca` |
| `Submission_ABC_123`| `submission-abc-123` |

## Next Steps

<CardGroup cols={2}>
<Card title="Prevent Self-Plagiarism" icon="arrows-rotate" href="/concepts/features/self-plagiarism/">Learn more about how to exclude previous submissions from the same student to prevent self-plagiarism.</Card>
<Card title="Submit a File" icon="file-arrow-up" href="/reference/actions/authenticity/submit-file/">See how to implement your Scan ID strategy when submitting a file for scanning.</Card>
</CardGroup>