The IAB Content Taxonomy is the standard classification system that tells programmatic buyers what category of content an ad will appear alongside. In CTV, content category signals travel in the OpenRTB bid request, enabling buyers to target or block specific content types — sports, news, drama, reality TV — and publishers to declare their content's nature for brand safety compliance. For India CTV publishers, proper taxonomy implementation is a prerequisite for premium programmatic demand.
What is the IAB Content Taxonomy
The IAB Content Taxonomy is a hierarchical classification system published by IAB Tech Lab. It assigns numeric codes to content categories at two levels: tier 1 (broad category) and tier 2 or tier 3 (specific subcategory). The current version for general content classification is Taxonomy 3.0; for video/CTV-specific content, IAB Video Content Taxonomy 2.2 is the relevant standard.
These taxonomy codes are passed in OpenRTB bid requests, VAST ad tags, and publisher supply chain metadata. Buyers can use them to whitelist categories they want to appear in, or blocklist categories they want to avoid. Brand safety vendors (IAS, DoubleVerify) use taxonomy signals alongside their own content analysis to make brand safety determinations.
Taxonomy versions in CTV
| Taxonomy | Purpose | CTV Relevance |
|---|---|---|
| IAB Content Taxonomy 1.0 | Original web content categories; 26 tier-1 categories | Legacy; still in circulation but being deprecated |
| IAB Content Taxonomy 2.2 | Expanded; 700+ categories; includes video content types | Widely used in CTV OpenRTB bid requests |
| IAB Tech Lab Taxonomy 3.0 | Unified content + audience + seller taxonomy | Emerging standard; some SSPs transitioning |
| IAB Video Content Taxonomy 2.2 | Video-specific categories; genre, rating, language | Primary standard for CTV content classification |
| GARM Brand Safety Floor | Defines unsafe/unsuitable content tiers | Used for brand safety determinations alongside taxonomy |
How taxonomy data travels in OpenRTB
In an OpenRTB bid request for CTV, content taxonomy information appears in the site / app and content objects. Key fields:
app.cat: Array of IAB content categories for the app (e.g., ["IAB17", "IAB17-18"] for Sports › Cricket)content.cat: Categories for the specific content item (episode, stream)content.genre: Freeform genre string (e.g., "Drama", "Reality", "Live Sports")content.language: Language of content (ISO-639-1 code; "hi" for Hindi, "ta" for Tamil)content.livestream: Boolean; 1 = live stream, 0 = on-demandcontent.contentrating: Content rating (e.g., "U", "U/A", "A" for Indian CBFC-style ratings)
Publishers who pass accurate, granular content metadata in these fields enable buyers to make better targeting decisions — and typically see higher CPMs because buyers are more confident in what they are buying.
Brand safety and blocklists
Brand safety configurations in DSPs often operate on content taxonomy codes. A brand might block IAB26 (Illegal Content), IAB25-3 (Hate Content), or any news content (IAB12) to avoid association with controversial news coverage. In CTV, these blocks apply at the content level, not just the app level — an advertiser can allow a news app but block specific news programmes or live news streams.
The GARM (Global Alliance for Responsible Media) Brand Safety Floor and Suitability Framework provides a more nuanced classification: unsafe, unsuitable, and suitable-with-context. GARM tiers map to IAB taxonomy categories, and IAS and DoubleVerify have implemented GARM alignment in their CTV verification products.
For India specifically: news content covering political unrest, social issues, and crime is a common brand safety exclusion. Advertisers should ensure their DSP blocklists cover IAB12 (News) subcategories beyond just the obvious ones — local language news streams may be miscategorised or carry no taxonomy at all.
Contextual targeting with content taxonomy
Without cookie-based audience targeting, content taxonomy becomes the primary lever for contextual ad targeting in CTV. A financial services advertiser can target IAB13 (Personal Finance) and IAB3 (Business) content. An automotive advertiser can target IAB2 (Automotive) content.
In India CTV, contextual targeting by content category is available via DV360 and The Trade Desk on publishers that pass category metadata. Genre-based targeting (drama, sports, reality) typically requires publisher-side configuration — the content metadata must be present in the bid request for the DSP to act on it.
The India CTV taxonomy gap
The honest assessment: content taxonomy coverage in India CTV is inconsistent. Problems:
- Many India publishers pass high-level tier-1 categories (e.g., IAB1 for Arts) without tier-2 or tier-3 specificity
- Regional language content is often miscategorised or carries the English-language parent category without language metadata
- Live sports events carry the app-level sports category but not event-specific metadata (IPL vs cricket in general vs other sports)
- Content ratings are inconsistently passed; some publishers omit
content.contentratingentirely
The practical implication: when buyers rely on content taxonomy for targeting or brand safety in India CTV, they should validate coverage before relying on it. Request a sample bid log from your SSP or DSP to check what taxonomy data is actually present for the inventory you are buying. Gaps are common and affect targeting accuracy more than most buyers realise.