> ## Documentation Index
> Fetch the complete documentation index at: https://docs.envisso.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Data Dictionaries

> Reference tables for integrating with Envisso — types, registration IDs, dispute codes, and MCCs.

This section covers all data elements you will need for the integration to Envisso and the relevant lookups to ensure you have all the information required.

<CardGroup cols={2}>
  <Card title="Data Types" icon="shapes" href="/data-dictionaries/data-types">
    String, integer, date, currency, and other valid data types and formats.
  </Card>

  <Card title="Merchant Registration ID Types" icon="id-card" href="/data-dictionaries/merchant-registration-id-types">
    Country-specific registration IDs (UEN, ACN, EIN, etc.) and their formats.
  </Card>

  <Card title="Dispute Reason Codes" icon="circle-exclamation" href="/data-dictionaries/dispute-reason-codes">
    Reason codes for Visa, Mastercard, Amex, Discover, Diner's, JCB, and UnionPay.
  </Card>

  <Card title="Merchant Category Codes" icon="tag" href="/data-dictionaries/merchant-category-codes">
    ISO 18245 MCC reference — searchable and filterable.
  </Card>
</CardGroup>