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

# SegmentCatalogField

> One field the condition grammar accepts. Generated from the segment data-structure registry.

<ResponseField name="category" type={<a href="/docs/api-reference/v3/reference/marketing/segment-condition-category">SegmentConditionCategory!</a>} required>
  Grouping in the builder.
</ResponseField>

<ResponseField name="dataType" type={<a href="/docs/api-reference/v3/reference/marketing/segment-field-data-type">SegmentFieldDataType!</a>} required>
  Which comparison object `whereCondition` must use.
</ResponseField>

<ResponseField name="description" type="String!" required>
  What the field measures.
</ResponseField>

<ResponseField name="id" type="String!" required>
  Stable id to put on `whereCondition.dimension` (attributes) or `event_filters[].dimension` (activities).
</ResponseField>

<ResponseField name="name" type="String!" required>
  Merchant-facing name.
</ResponseField>

<ResponseField name="needsTokenOptions" type="Boolean!" required>
  If true, list allowed values with `segmentTokenFieldOptions` before writing the condition.
</ResponseField>

<ResponseField name="operators" type="[String!]!" required>
  Stored `comparison.operator` values for this data type. Empty for boolean and custom-field (those pick a nested comparison).
</ResponseField>

<ResponseField name="tokenPrerequisiteCount" type="Int">
  Parent tokens required in `prerequisiteValues`. Null: none. 0 (custom-fields): list declarations with no prerequisites, then pass `[declarationId]` to list values. Country before state is 1; country+state before city is 2.
</ResponseField>

<ResponseField name="unit" type={<a href="/docs/api-reference/v3/reference/marketing/segment-field-unit">SegmentFieldUnit</a>}>
  How to present a numeric value. Null when not numeric.
</ResponseField>


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