App.cattax

Names the taxonomy used by App.cat, App.sectioncat, and App.pagecat, as a value from the AdCOM Category Taxonomies list. Defaults to 1, IAB Content Category Taxonomy 1.0. Added in OpenRTB 2.6.

CurrentintegerOptionalSince 2.6-202204

Field facts

Path: app.cattax
Object: App
Type: integer
Default: 1
Requirement: Optional
Added: OpenRTB 2.6-202204
Values: AdCOM list Category Taxonomies
Spec section: 3.2.14

How it is used

Choose a content taxonomy: 1 or 2 for Content Category Taxonomy 1.0 or 2.0, 5 or 6 for Content Taxonomy 2.1 or 2.2, 7 for 3.0, or 9 for 3.1. Values of 500 and above are reserved for vendor taxonomies agreed with the buyer.

Allowed values

Value	Meaning
`1`	IAB Tech Lab Content Category Taxonomy 1.0: The original IAB content categories with codes like IAB1-1; deprecated, but still the default when `cattax` is omitted.
`2`	IAB Tech Lab Content Category Taxonomy 2.0: Content Taxonomy 2.0, the first version with numeric IDs; deprecated in favor of later releases.
`3`	IAB Tech Lab Ad Product Taxonomy 1.0: Categories for the product or service an ad promotes, used for ad blocking and creative labeling.
`4`	IAB Tech Lab Audience Taxonomy 1.1: Audience Taxonomy 1.1, which describes people (demographics, interests, purchase intent) rather than content or ads.
`5`	IAB Tech Lab Content Taxonomy 2.1: Content Taxonomy 2.1, a 2.x revision suitable for content classification.
`6`	IAB Tech Lab Content Taxonomy 2.2: Content Taxonomy 2.2, the newest 2.x version in this list.
`7`	IAB Tech Lab Content Taxonomy 3.0: Content Taxonomy 3.0, the first release of the 3.x generation.
`8`	IAB Tech Lab Ad Product Taxonomy 2.0: Ad Product Taxonomy 2.0, the newer of the two ad product versions in this list.
`9`	IAB Tech Lab Content Taxonomy 3.1: Content Taxonomy 3.1, also the default taxonomy for `Content.genres` when `Content.gtax` is absent.
`500+`	Vendor-specific codes: Vendor-specific taxonomies, such as an exchange's own category codes, agreed between the parties.

Example

Where the field sits in a payload, with everything else left out:

{
  "id": "req-1",
  "app": {
    "cattax": 9
  }
}

Common mistakes

Assuming BidRequest.cattax also covers app categories. Each object declares its own taxonomy.

Version history

Added in OpenRTB 2.6-202204, and present in the latest snapshot. The table shows how each version's spec text types the field.

Versions	Type in the spec	Required	Deprecated
2.6-202204	Added in the first 2.6 release, published without a structured text archive; the 2.6-202210 republication is the first tagged text.
2.6-202210 to 2.6-202606	integer, default 1	No	No

Versioned rules that name this field

openrtb.2.6.cattax OpenRTB 2.6 standardized taxonomy selection with cattax across request and bid objects.