--- title: Advertising: The Shape Of The Answer | daily.dev description: Advertising agreed on its data shapes more than fifteen years ago, and OpenRTB and the IAB content taxonomy govern them, but almost none of it is published as... canonical: https://daily.dev/posts/advertising-the-shape-of-the-answer-o8m7uezt2 twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Advertising: The Shape Of The Answer | daily.dev og:description: Advertising agreed on its data shapes more than fifteen years ago, and OpenRTB and the IAB content taxonomy govern them, but almost none of it is published as... og:url: https://daily.dev/posts/advertising-the-shape-of-the-answer-o8m7uezt2 og:image: https://api.daily.dev/og/posts/o8M7UEZt2.png og:image:alt: Advertising: The Shape Of The Answer og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Advertising: The Shape Of The Answer **[API Evangelist](https://daily.dev/sources/apievangelist)** · 7 min read · 0 upvotes · 0 comments ## Summary Advertising agreed on its data shapes more than fifteen years ago, and OpenRTB and the IAB content taxonomy govern them, but almost none of it is published as machine-readable schema a constrained decoder can use. OpenRTB 2.6 defines BidRequest and BidResponse objects with a tmax bidding deadline, and the IAB Content Taxonomy is at version 3.1, with version 1.0 deprecated. Among the 25 repos in the adtech cohort tracked, 6 hold JSON Schema, and the exchanges the source examined document their OpenRTB subset as prose tables. Constraining a model's output to these schemas would help make bid requests and brand-safety classification deterministic and auditable. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What is the current version of the OpenRTB specification used for real-time bidding? OpenRTB is governed by the IAB Tech Lab and the current specification is version 2.6, still being revised, with its most recent GitHub release tagged 2.6-202606. It defines a BidRequest made of Imp objects carrying Banner, Video, Audio or Native objects, a Pmp holding Deal objects, plus Site or App, Device, User, Regs and SupplyChain, with responses returned as a BidResponse holding SeatBid and Bid objects. _Track spec updates like OpenRTB 2.6 on daily.dev so your bidding integration doesn't fall out of sync._ ### What IAB content taxonomy version should I use for categorizing ad inventory, and is version 1.0 still valid? The IAB Tech Lab Content Taxonomy is at version 3.1, released December 2024, and version 1.0 is explicitly deprecated and should not be used. The Tech Lab has also published a taxonomy mapper for moving from version 2.x to 3.0, and the cattax field in OpenRTB 2.6 specifies which taxonomy version is in use. _Developers mapping ad categories can follow daily.dev to stay ahead of taxonomy version deprecations._ ### Why does batch-invariant inference matter for AI models used in ad bidding or content classification? Without batch-invariance, the same page or bid request could receive a different classification depending on what else was being processed in the same batch, making brand-safety enforcement and blocked-category rules apply unevenly. Since exchanges operate within a strict tmax time budget at huge volume, a deterministic, auditable answer is needed so the same input always produces the same taxonomy id or bid response. _Engineers building deterministic AI pipelines for ad systems can track batch-invariance research on daily.dev._ ## Similar posts on daily.dev - [How to Build an OpenRTB Bid Request Handler: A Developer's Guide to Programmatic Advertising](https://daily.dev/posts/how-to-build-an-openrtb-bid-request-handler-a-developer-s-guide-to-programmatic-advertising-bmpcnujj2) · SitePoint · 0 upvotes · 0 comments - [How Programmatic Advertising Works](https://daily.dev/posts/how-programmatic-advertising-works-drrxp4qan) · freeCodeCamp · 0 upvotes · 0 comments - [JSON Schema Governs the Shape of Your Data](https://daily.dev/posts/json-schema-governs-the-shape-of-your-data-mxmz1qsyh) · API Evangelist · 0 upvotes · 0 comments - [Schema Markup for Security Content: The Structured Data That Actually Gets Cybersecurity Vendors Cited by AI](https://daily.dev/posts/schema-markup-for-security-content-the-structured-data-that-actually-gets-cybersecurity-vendors-cit-vgdgqzqfm) · Security Boulevard · 0 upvotes · 0 comments - [The media industry is becoming a prediction economy](https://daily.dev/posts/the-media-industry-is-becoming-a-prediction-economy-4scji5j3z) · databricks · 2 upvotes · 0 comments --- Tags: [#llm](https://daily.dev/tags/llm), [#architecture](https://daily.dev/tags/architecture) [View this post on daily.dev](https://daily.dev/posts/advertising-the-shape-of-the-answer-o8m7uezt2) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Advertising: The Shape Of The Answer","url":"https://daily.dev/posts/advertising-the-shape-of-the-answer-o8m7uezt2","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/advertising-the-shape-of-the-answer-o8m7uezt2"},"datePublished":"2026-10-28T11:24:53.595Z","dateModified":"2026-10-28T15:02:56.404Z","description":"Advertising agreed on its data shapes more than fifteen years ago, and OpenRTB and the IAB content taxonomy govern them, but almost none of it is published as...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/cddc262ef6f058851b147d77228c7869?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/cddc262ef6f058851b147d77228c7869?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"API Evangelist","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"API Evangelist","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/a36244ae67bc4f41a605f780267ecb5f","url":"https://daily.dev/sources/apievangelist"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/advertising-the-shape-of-the-answer-o8m7uezt2","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"llm,architecture","timeRequired":"PT7M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"API Evangelist","item":"https://daily.dev/sources/apievangelist"},{"@type":"ListItem","position":3,"name":"Advertising: The Shape Of The Answer"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/advertising-the-shape-of-the-answer-o8m7uezt2#faq","mainEntity":[{"@type":"Question","name":"What is the current version of the OpenRTB specification used for real-time bidding?","acceptedAnswer":{"@type":"Answer","text":"OpenRTB is governed by the IAB Tech Lab and the current specification is version 2.6, still being revised, with its most recent GitHub release tagged 2.6-202606. It defines a BidRequest made of Imp objects carrying Banner, Video, Audio or Native objects, a Pmp holding Deal objects, plus Site or App, Device, User, Regs and SupplyChain, with responses returned as a BidResponse holding SeatBid and Bid objects. Track spec updates like OpenRTB 2.6 on daily.dev so your bidding integration doesn't fall out of sync."}},{"@type":"Question","name":"What IAB content taxonomy version should I use for categorizing ad inventory, and is version 1.0 still valid?","acceptedAnswer":{"@type":"Answer","text":"The IAB Tech Lab Content Taxonomy is at version 3.1, released December 2024, and version 1.0 is explicitly deprecated and should not be used. The Tech Lab has also published a taxonomy mapper for moving from version 2.x to 3.0, and the cattax field in OpenRTB 2.6 specifies which taxonomy version is in use. Developers mapping ad categories can follow daily.dev to stay ahead of taxonomy version deprecations."}},{"@type":"Question","name":"Why does batch-invariant inference matter for AI models used in ad bidding or content classification?","acceptedAnswer":{"@type":"Answer","text":"Without batch-invariance, the same page or bid request could receive a different classification depending on what else was being processed in the same batch, making brand-safety enforcement and blocked-category rules apply unevenly. Since exchanges operate within a strict tmax time budget at huge volume, a deterministic, auditable answer is needed so the same input always produces the same taxonomy id or bid response. Engineers building deterministic AI pipelines for ad systems can track batch-invariance research on daily.dev."}}]} ```