Prefix Requirements for Key Variables

This article describes the prefixes you must attach to key variables when creating trait rules.

Purpose of Key Variable Prefixes

When you create Trait Builder rules, it is important to preface the key variable with a recommended prefix. These prefixes identify the type of data passed in and help avoid namespace conflicts within Audience Manager. Generally, you can give a variable any name, but data for a rule will not process if the key variable name does not match the variable name in an event call.

Prefixes for Key Variables

The following table defines the common prefixes used by Trait Builder.
Key variable prefix Identifies the variable
c_

As customer specific. This is key data sent in from your own properties.

d_

At the Audience Manager level. This data is uniform across the Audience Manager ecosystem. See Supported Attributes for DCS API Calls for a more complete list.

h_

That contains HTTP header information. Includes header parameters such as referer, IP, accept-language, etc.

p_

Our Data Collection Servers allow passing of private parameters. Basically, any parameter that starts with p_ will be used for trait evaluation, but it will not be logged downstream, nor stored.

Example: given /event?p_age=23 and a trait like YoungPeople = p_age < 25, the trait will be realized, but the p_age=23 key-value pair will be dropped after the request and will not be logged.