Content.gtax

Names the taxonomy that Content.genres values come from, using the AdCOM Category Taxonomies list. Defaults to 9, IAB Content Taxonomy 3.1. Added in 2.6-202501.

CurrentintOptionalSince 2.6-202501

Field facts

Path: app.content.gtax, dooh.content.gtax, site.content.gtax
Object: Content
Type: int
Default: 9
Requirement: Optional
Added: OpenRTB 2.6-202501
Values: AdCOM list Category Taxonomies
Spec section: 3.2.16

How it is used

Every cattax field defaults to 1, but gtax defaults to 9. When it is absent, genres are read against the CTV Genre Mapping subset of Content Taxonomy 3.1, so most sellers can omit it. Set it only when the genre IDs come from another taxonomy, such as a vendor list at 500 or above.

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": {
    "content": {
      "gtax": 9
    }
  }
}

Common mistakes

Copying the Content.cattax value into gtax. The two describe different fields and have different defaults.

Version history

Added in OpenRTB 2.6-202501, 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
2.6-202501	Listed in this release's notes; IAB's tagged spec file for it does not include the field yet.
2.6-202505 to 2.6-202606	int, default 9	No	No