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

# Proprietary Columns

> How to recognize SourceMedium-derived columns (the `sm_` prefix) and what they represent.

### Overview

The prefix `sm_` in a column name indicates that the column is proprietary to SourceMedium, meaning that the data contained within is a
function of SourceMedium's data transformations. This prefix helps to quickly identifying SourceMedium-specific fields that have been
materially enriched through a process of cleaning or imputing.

For example, `sm_source_medium` is a field derived from last-click attribution data from Shopify, Google Analytics, GA4, Elevar,
Blotout, Littledata, referring domains, and other sources of last-click UTM parameters.