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

# Glossary

> Key Cotality terms, identifiers, and standards — a shared vocabulary for business teams, developers, and AI agents.

## Identifiers and entities

| Term                         | Definition                                                                                                                                        |
| ---------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------- |
| **CLIP**                     | Cotality property identifier — a unique, stable ID for a property; the join key across all data assets. See [Identifiers](/ontology/identifiers). |
| **APN**                      | Assessor's parcel number — county-assigned parcel identifier; format varies by county.                                                            |
| **Parcel**                   | The legal land unit a property sits on.                                                                                                           |
| **Structure**                | A building on a parcel; a property may have one or more.                                                                                          |
| **Property characteristics** | The full set of land, structure, and ownership attributes for a property.                                                                         |
| **USPS standardization**     | Normalization of a raw address to USPS Publication 28 format before CLIP resolution.                                                              |

## Market and risk

| Term              | Definition                                                                                                                |
| ----------------- | ------------------------------------------------------------------------------------------------------------------------- |
| **HPI**           | Cotality home price index — measures residential price movement over time.                                                |
| **HPI forecast**  | Model projection of future home price appreciation or depreciation. A forward estimate, not an observation.               |
| **Case-shiller**  | Widely cited home-price index family produced by Cotality (formerly CoreLogic).                                           |
| **Acute peril**   | Event-driven hazard (wildfire, flood, hurricane, earthquake, severe storm).                                               |
| **Chronic peril** | Slow-onset climate stressor (e.g., heat index, drought).                                                                  |
| **Return period** | The average interval between hazard events of a given severity (e.g., 100-year flood = event with 1% annual probability). |
| **Age of roof**   | Cotality's statistically modelled estimate of roof age — not a county record. Always check `yearBuiltModeledIndicator`.   |

## Geography

| Term          | Definition                                                                                                       |
| ------------- | ---------------------------------------------------------------------------------------------------------------- |
| **ZIP**       | 5-digit postal area; may span county lines.                                                                      |
| **County**    | Administrative county unit; basis for tax records and licensing.                                                 |
| **CBSA**      | Core-based statistical area — a metropolitan statistical area (metro market).                                    |
| **FIPS code** | Federal information processing standard code identifying a state or county (e.g., `06037` = Los angeles county). |

## Interfaces and platform

| Term                  | Definition                                                                                                                                 |
| --------------------- | ------------------------------------------------------------------------------------------------------------------------------------------ |
| **MCP**               | Model context protocol — open standard connecting AI agents to tools and data at runtime.                                                  |
| **A2A**               | Agent-to-agent protocol — the communication protocol used by Cotality's valuation AI agents.                                               |
| **Response envelope** | The common `{ success, count, data, messages }` wrapper on every Cotality response. See [Response envelope](/reference/response-envelope). |
| **Analyticsfilter**   | The shared input object for all five market and HPI analytics tools (`geography_filter` + optional `time_range`).                          |
| **Entitlement**       | Licensed access to a specific data asset or tool, enforced at the token level.                                                             |

## Industry standards

| Term            | Definition                                                                                                                                                                  |
| --------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **MISMO**       | Mortgage industry standards maintenance organization — XML data standard for mortgage transactions. Cotality property fields map to MISMO Residential XML v3.x.             |
| **ACORD**       | Association for cooperative operations research and development — P\&C insurance data standard. Cotality construction and roof codes map to ACORD structural rating fields. |
| **USPS Pub 28** | USPS postal addressing standards — used to normalize addresses before CLIP resolution.                                                                                      |
| **OGC WKT**     | Well-known text — geospatial geometry format (OGC standard). Building footprint geometry is returned in WKT, compatible with PostGIS, ArcGIS, and QGIS.                     |
| **UAD**         | Uniform appraisal dataset — FHFA standard for appraisal data. Cotality compliance tools validate against UAD rules.                                                         |
| **UCDP**        | Uniform collateral data portal — GSE submission portal for appraisal data.                                                                                                  |

<Tip>
  Cotality was formerly **CoreLogic** (rebranded 2025). Legacy product names (CLIP, Case-Shiller,
  AVM) retain the CoreLogic lineage and may appear in legacy API field names. See
  [Platform overview](/getting-started/overview).
</Tip>