Category taxonomies
Category taxonomies tell the receiver which IAB Tech Lab vocabulary a set of category IDs comes from: content, ad product or audience, and which version. OpenRTB 2.6 sends the value in a cattax field on each object that carries categories, plus Content.gtax for genres. Every cattax defaults to 1, the deprecated Content Category Taxonomy 1.0, so the field matters most when it is missing.
Values
| Value | Name | What it means |
|---|---|---|
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. |
Fields that use this list
How to use it
Each object that carries categories has its own cattax, and it describes only the category arrays in that object. BidRequest.cattax covers BidRequest.bcat and BidRequest.acat. Site.cattax and App.cattax cover their cat, sectioncat and pagecat. Publisher.cattax, Content.cattax and Producer.cattax cover their own cat, and Bid.cattax covers Bid.cat. Nothing is inherited from a parent object, so a site and its content can use different taxonomies in the same request. Content.gtax works the same way for Content.genres but defaults to 9. Use content taxonomies for what a page or stream is about and ad product taxonomies for what an ad sells.
Common mistakes
- Sending Content Taxonomy 2.x or 3.x IDs with no
cattax. The default is 1, so the buyer looks the IDs up in the 1.0 code list and finds nothing, or the wrong category. - Setting
BidRequest.cattaxand expecting it to describesite.cat. The request-level field covers onlybcatandacat. - Mixing taxonomies in one array, such as "IAB25" next to a numeric ID. One
cattaxdescribes the whole array, so split the data or convert it. - Using the audience taxonomy (4) for content or ad categories. The IDs are not interchangeable.
- Sending a value below 500 that the list does not define. rtblint reports it as
openrtb.value.invalid.
Validation
On OpenRTB 2.6 snapshots, RTBlint reports a value outside this list as openrtb.value.invalid. Paste a request into the tester to check the values you send.
Related lists
All lists are on the enumerated lists index.