Google updated its Search Central documentation on July 10, 2026 with the most recent in a series of changes affecting how website owners and online merchants structure information for search results, according to the company's official changelog. Two earlier entries from the same week are also relevant to retailers and publishers: a July 7 addition to the Product structured data guidelines that lets merchants specify both a custom product category and Google's own product taxonomy inside the same schema.org markup, and a July 1 simplification of AMP documentation tied to a change in how Search handles Accelerated Mobile Pages.

The July 7, 2026 update to the Merchant listing documentation adds detail on how the Product.category property can accept two distinct data types: plain text and a new CategoryCode object. According to Google, this brings structured data markup into alignment with two attributes long available in Merchant Center product feeds - product_type, which lets a merchant define its own internal categorization, and google_product_category, which maps a product to Google's standardized taxonomy. Previously, merchants adding Product markup directly to their web pages had a single category property to work with, without a formal mechanism for supplying both a merchant-defined label and a Google-defined one side by side.

The same July 7 changelog entry also details a clarification to how merchants can specify the exact window during which a sale price applies. Google added a new "Sale duration" section to the Merchant listing guide, explaining how the validFrom, validThrough, and priceValidUntil schema.org properties should be used to set a start and end date for a promotional price. A third update, dated July 1, simplified Google's AMP documentation and changed how Search routes users to AMP pages, a shift PPC Land had already reported based on Google's own notifications to advertisers and publishers two days prior.

What changed in merchant listing category markup

Structured data operates as a translator between a webpage's visible content and the systems that decide what appears in Google Search results and Shopping surfaces. For years, Google's Product markup guidelines defined a single categoryproperty, described simply as text specifying the product's category. The July 7 update replaces that simplicity with two explicit paths, according to the updated documentation.

The first path is unchanged in spirit: merchants can still supply a plain text string as a custom product type, similar to the product_type attribute long used in Merchant Center feeds. Google's documentation recommends keeping these custom strings under 750 characters. The second path is new to structured data markup, even though the underlying concept is not new to Merchant Center. To specify a Google Product Category, called GPC in the documentation, a merchant now sets the @type field to CategoryCode, points inCodeSet to a Google Product Taxonomy URL, and sets codeValue to either a numeric GPC ID or a full category path using the > separator, such as "Apparel & Accessories > Clothing > Dresses." Both formats accept numeric IDs as well as text paths, and the property can hold multiple values at once, so a merchant is not forced to choose only one classification system.

Because the category property accepts an array, Google's documentation shows an example combining several values in a single product listing: two CategoryCode entries referencing different points in Google's taxonomy, alongside two plain text strings representing custom categories such as "Dresses" and "Special Occasion > Wedding & Bridal Party Dresses." That flexibility matters for larger retailers whose internal catalog systems rarely map neatly onto Google's own taxonomy, since it lets a single product page satisfy both an internal reporting need and Google's classification requirements without a workaround.

Sale duration gets a dedicated section

Separately, but published under the same July 7 changelog entry, Google added a new "Sale duration" section addressing a gap that had previously required merchants to infer best practice from scattered property definitions. The guidance centers on three schema.org properties already defined for pricing: validFrom, which marks when a sale price becomes active; and either validThrough or priceValidUntil, both of which mark when the sale price stops applying. All three accept values in ISO 8601 format, and Google's documentation gives a specific example format: "2025-12-31T23:59:59+01:00."

The guidance sets out several best practices rather than a single rigid rule. Merchants should provide both a start and an end date to define the sale period clearly, and the start date should be earlier than or equal to the end date. Google's documentation recommends including both time and time zone information for accuracy across its systems, since a sale price that expires without a clear time zone attached introduces ambiguity about exactly when the listing should revert to its regular price.

Placement of these properties depends on where the sale price itself lives in the markup. If the sale price sits directly on the Offer node - meaning the price property on that node already represents the discounted amount - then validFrom and either validThrough or priceValidUntil belong on that same Offer node. If instead the sale price is defined inside a separate PriceSpecification node, typically one that does not carry a priceType property when a strikethrough price is also present, the duration properties belong on that specific PriceSpecification node instead. Google's documentation notes one exception: priceValidUntil is not applicable to the PriceSpecification type, so only validFrom and validThrough can be used there.

The practical effect is that Google's systems can now more precisely determine whether a listed sale price should still be honored at the moment a shopper sees it in search results. A listing whose priceValidUntil date has passed may not display at all, according to the broader Offer property documentation, which makes accurate date and time formatting a matter of listing eligibility rather than a cosmetic detail.

The canonicalization update three days later

Three days after the merchant listing changes, on July 10, 2026, Google updated a separate piece of documentation: its canonicalization troubleshooting guide. According to the changelog, the update adds clarifications on re-evaluation time - specifically, how long it takes for canonicalization changes to take effect after a website owner has made them. Google's stated reason is to provide better expectations about the delay between implementing a canonical tag change and seeing that change reflected in how Google treats the page.

Canonicalization is the process by which Google decides which version of a URL to treat as authoritative when multiple URLs contain duplicate or near-duplicate content, a recurring technical concern for large websites with parameter-heavy URLs, faceted navigation, or multiple domain variants. Google's Search Relations team addressed related canonicalization topics earlier in 2026: John Mueller cautioned in February against over-auditing redirect chains for SEO purposes, and the topic featured prominently in the agenda Google set for its first European Search Central Live Deep Dive event, scheduled for Barcelona from September 30 through October 2, 2026, where "duplication and canonicalization" are billed as two of the more persistent technical headaches facing large sites.

The July 10 update does not change the underlying mechanics of how canonicalization works. It adds expectation-setting language about timing, addressing a common source of confusion for website owners who make a canonicalization fix and then wonder, sometimes for weeks, whether Google has actually recognized it.

AMP documentation change already in effect

The third change in this week's documentation cycle is dated July 1, 2026, and concerns Google's Accelerated Mobile Pages guidance. According to the changelog, Google simplified its AMP documentation by removing outdated references to the AMP viewer, the AMP Cache, and signed exchanges. The stated reason ties directly to a functional change in how Search handles AMP pages: starting July 1, Google Search began connecting users directly to a publisher's own AMP-hosted pages rather than routing them through a Google-hosted cached copy, which had been the original design of the AMP system since its introduction.

This shift had already reached the marketing and publishing community before Google's documentation update caught up with it. PPC Land reported on July 2, 2026 that Greg Finn of Cypress North and Barry Schwartz of Search Engine Roundtable discussed the AMP routing change in a recorded conversation published that day, describing the shift as taking effect "starting today" relative to the recording, "to simplify and reduce maintenance efforts for publishers who are creating AMP content." Google's own documentation frames the change identically: the update states that publishers creating AMP content no longer need to update the AMP cache or configure signed exchanges, and that AMP content will continue to rank the same as any other web page.

The July 1 documentation update reflects a technical description of a change that had already been communicated through other channels rather than a new decision in itself. Google's Search Central documentation and its product-facing rollout do not always publish on the same day, and this week's changelog entries show a version of that gap: the AMP functional change took effect July 1, its documentation appeared the same day, but the CPA bidding recording that first surfaced the AMP shift publicly for many advertisers ran a day later, on July 2.

Why this matters for the marketing community

For retailers running Shopping campaigns or maintaining product structured data outside Merchant Center, the July 7 category markup change closes a gap that has existed since Google first introduced merchant listing structured data. Retailers previously choosing between a custom category label and Google's own taxonomy inside their schema.org markup can now supply both, matching what Merchant Center feeds have supported for years through the product_type and google_product_category attributes. Retailers who rely primarily on Merchant Center feeds rather than on-page structured data will see no immediate change, since the feed attributes this markup update mirrors already existed.

The sale duration clarification carries a narrower but sharper practical stake: a promotional price whose priceValidUntil date has already passed risks disappearing from search results entirely, according to Google's broader documentation on Offer properties. Retailers running time-boxed promotions, a category that spans everything from flash sales to seasonal discounts, now have an explicit reference for how to format start and end dates so that Google's systems recognize the sale window accurately rather than defaulting the listing to an indeterminate state.

The canonicalization update is less about a specific action item and more about expectation management. Large sites managing extensive redirect or parameter structures have historically had limited visibility into how long a canonicalization fix takes to register with Google's systems, and this update gives SEO practitioners a documented reference point rather than accumulated folk knowledge from forums and community threads.

Google's broader documentation cadence this year has continued to favor commercial structured data - merchant listings, loyalty programs, shipping and return policies - over reference-oriented rich result types, several of which Google has deprecated or removed entirely in 2025 and 2026. FAQ rich results stopped appearing in Google Search as of May 7, 2026, following the earlier removal of practice problem structured data support beginning in January 2026. Against that backdrop, the July 7 category and sale-duration additions read as continued investment in the shopping-adjacent side of structured data even as Google narrows support elsewhere.

Website owners evaluating this week's changes alongside Google's other recent documentation updates will also find a related clarification already settled: Google added a note to its AI optimization guide on June 15, 2026, stating that llms.txt files carry no ranking effect for Google Search, positive or negative, addressing a question that had circulated among SEO practitioners since the file format's original 2024 proposal.

Timeline

  • July 1, 2026 - Google simplifies AMP documentation, removing references to the AMP viewer, AMP Cache, and signed exchanges, and begins routing Search users directly to publisher-hosted AMP pages instead of Google-cached copies.
  • July 2, 2026 - Google Ads sends notification emails to advertisers about a separate bidding change; a recorded industry conversation the same day describes the AMP routing shift publicly for the first time to many advertisers and publishers.
  • July 7, 2026 - Google adds the CategoryCode type to Product structured data, aligning schema.org markup with Merchant Center's product_type and google_product_category feed attributes, and publishes a new Sale duration section covering validFrom, validThrough, and priceValidUntil properties.
  • July 10, 2026 - Google updates its canonicalization troubleshooting guide with clarifications on how long re-evaluation takes after a canonicalization change is made.

Summary

Who: Google's Search Central documentation team, affecting website owners, online merchants, and SEO professionals who implement structured data or manage canonicalization on their sites.

What: Three separate documentation updates published within a ten-day span - a July 1 simplification of AMP documentation tied to a change in how Search routes users to AMP pages, a July 7 addition of the CategoryCode property type to Product structured data alongside a new Sale duration section for pricing properties, and a July 10 clarification of canonicalization re-evaluation timing in the troubleshooting guide.

When: The AMP documentation changed July 1, 2026. The merchant listing category and sale duration updates were published July 7, 2026. The canonicalization troubleshooting guide was updated July 10, 2026, the most recent of the three at the time of this report.

Where: All three updates appear on Google's Search Central documentation site, part of the company's official reference material for website owners, developers, and merchants operating in Google Search and Google Shopping.

Why: The changes reflect Google's ongoing pattern of refining structured data guidance for commercial use cases - merchant category classification and sale pricing - while separately addressing longstanding technical questions about canonicalization timing and AMP's transition away from Google-hosted caching.