How many terms does the SEO for Solos glossary define?

The SEO for Solos glossary defines 82 SEO and answer engine terms across 14 categories, each with a definition, why it matters, and how it is measured.

Is the glossary free?

The SEO for Solos glossary is free and needs no account. Every term links to the playbook chapter that explains the mechanism in full.

SEO and AEO glossary: 82 terms

SEO for Solos defines 82 terms, each with what it means, why it matters, and how it is measured. Every term links to the chapter that explains the mechanism in full.

Terms

Foundations

Canonical URL: A canonical URL is the address a site declares to be the authoritative version of a page, using a link element with rel=canonical.
Duplicate content: Duplicate content is substantially identical content available at more than one URL.
Soft 404: A soft 404 is a page that says not found in words while returning a 200 status code.
Trailing slash: A trailing slash is the final forward slash on a URL path, which makes it a different URL to a crawler.
URL normalisation: URL normalisation is reducing the many ways a URL can be written to one canonical form.

Failure modes

Canonical chain: A canonical chain is a sequence where page A declares B as canonical and B declares C, rather than pointing directly at the final URL.
Canonical loop: A canonical loop is a pair of pages that each declare the other as canonical.
Doorway page: A doorway page is one of many near-identical pages created to capture query variations, offering no unique value.
Manual action: A manual action is a human-applied penalty from a search engine, listed in Search Console.
Thin content: Thin content is a page with little or no value to a reader, whether generated, scraped or simply empty.

Crawling and indexing

Bot economics: Bot economics is deciding crawler access based on whether a crawler can return a visit or a citation for the bandwidth it consumes.
Crawl budget: Crawl budget is the number of URLs a search engine will fetch from a site in a given period.
GPTBot: GPTBot is OpenAI's training crawler, distinct from OAI-SearchBot which builds the ChatGPT search index.
hreflang: hreflang is an annotation declaring alternate language or regional versions of a page.
IndexNow: IndexNow is a protocol for pushing changed URLs to participating search engines rather than waiting to be crawled.
lastmod: lastmod is the sitemap field declaring when a URL's content last changed.
noindex: noindex is a robots directive, in a meta tag or an HTTP header, telling a search engine not to include a page in its index.
Orphan page: An orphan page is a URL reachable from the sitemap but not linked from anywhere on the site.
robots.txt: robots.txt is a plain text file at a site's root declaring which user agents may fetch which paths.
Sitemap: A sitemap is an XML file listing a site's URLs with optional last-modified dates, change frequencies and priorities.

Measurement

CTR: Click-through rate is the proportion of impressions that produce a click.
Impression: An impression is a search result being shown to a user, whether or not it was clicked.
Indexation: Indexation is whether a URL has been added to a search engine's index and is eligible to appear in results.
Query segmentation: Query segmentation is analysing search performance by page tier rather than in aggregate.
Ranking: Ranking is a page's position in results for a given query.
SERP: A SERP is a search engine results page.

Structured data

Entity: An entity is a distinct thing a search engine recognises: a person, an organisation, a product, a concept.
JSON-LD: JSON-LD is a JSON-based format for linked data, and the format search engines recommend for structured data.
Rich result: A rich result is a search result rendered with extra visual elements derived from structured data.
Schema graph: A schema graph is a single JSON-LD document holding an @graph array of nodes that reference each other by @id.
Structured data: Structured data is machine-readable markup describing a page's meaning, most often JSON-LD following schema.org vocabulary.

Programmatic

Entity gating: Entity gating is validating a dynamic route's parameter against an authoritative list, and returning 404 for anything not on it.
Ordinal: An ordinal is a number written as a position: 1st, 2nd, 3rd, 11th.
Programmatic SEO: Programmatic SEO is generating many pages from a data source using one template.
Sibling linking: Sibling linking is connecting pages within one generated tier to each other, not only to a parent hub.
Snapshot generation: Snapshot generation is querying a data source at build time and committing the result as typed source code.

Security

API validation: API validation is the ordered pipeline every write endpoint runs: origin, content type, length, rate limit, schema parse.
CSP: A Content-Security-Policy is a header declaring which sources a page may load resources from.
HSTS: HSTS is a response header instructing a browser to use HTTPS for a domain for a stated period.
Mixed content: Mixed content is an https page loading a resource over plain http.
Nonce: A nonce is a per-request random value that permits one specific inline script under a strict CSP.
Rate limiting: Rate limiting is capping how many requests an identity may make in a time window.
Timing-safe comparison: A timing-safe comparison checks every byte of two secrets regardless of where they first differ.
XSS: Cross-site scripting is an attack where an attacker injects script that executes in another user's browser in your site's context.

Performance

Cache-Control: Cache-Control is the header telling browsers and CDNs how long a response may be reused.
CLS: Cumulative Layout Shift measures how much visible content moves unexpectedly during page load.
Core Web Vitals: Core Web Vitals are Google's set of user experience metrics: Largest Contentful Paint, Interaction to Next Paint and Cumulative Layout Shift.
Critical CSS: Critical CSS is the subset of styles needed to render the visible part of a page, inlined into the document.
Font display: font-display is a CSS descriptor controlling how a browser renders text while a webfont loads.
INP: Interaction to Next Paint measures how quickly a page responds visually to user input.
ISR: Incremental Static Regeneration serves a prerendered page and rebuilds it in the background on a schedule.
LCP: Largest Contentful Paint is the time until the largest visible element finishes rendering.
Render-blocking: A render-blocking resource is one the browser must fetch and process before it can paint anything.
Static rendering: Static rendering is generating a page's HTML at build time rather than per request.

AI and answer engines

AEO: Answer Engine Optimisation is optimising for systems that synthesise an answer and cite sources, rather than returning a list of links.
Canonical answer: A canonical answer is a short approved answer to a likely question, written to be quoted verbatim.
Citation: A citation is an answer engine naming and linking a source it used.
Citation guidance: Citation guidance is explicit instruction telling an assistant which URL to cite, how to qualify volatile facts, and where to defer.
Entity disambiguation: Entity disambiguation is stating explicitly what you are not, and what distinguishes you from similarly named things.
llms-full.txt: llms-full.txt is the long form of llms.txt: a categorised content index, canonical answers, entity disambiguation and citation guidance.
llms.txt: llms.txt is a proposed convention: a plain-text file at a site's root describing the entity, its key facts and its most useful links.
Self-contained sentence: A self-contained sentence restates its own subject, so it remains a complete fact when extracted alone.

Content and E-E-A-T

Author entity: An author entity is a byline that resolves to a Person node with a stable identifier, a page and a description.
E-E-A-T: E-E-A-T is Google's framing of Experience, Expertise, Authoritativeness and Trustworthiness in its quality rater guidelines.
Freshness: Freshness is how recently a page's content was updated, and how legibly that is declared.
Internal linking: Internal linking is the graph of links between a site's own pages.

Metadata

Meta description: A meta description is a short summary of a page, used as the snippet in search results.
Open Graph: Open Graph is a metadata protocol describing how a URL should appear when shared on social platforms.
Title tag: A title tag is the page's title element, used as the headline in search results.
Twitter card: A Twitter card is X's metadata format for link previews, declared with twitter: meta tags.

Accessibility

Focus ring: A focus ring is the visible outline showing which element currently has keyboard focus.
Landmark: A landmark is a semantic region of a page: header, nav, main, footer, aside.
Semantic HTML: Semantic HTML is using elements for their meaning rather than their appearance.
Skip link: A skip link is a keyboard-focusable link, first in the tab order, that jumps to the main content.
Tap target: A tap target is the touchable area of an interactive element.
Viewport zoom: Viewport zoom on focus is iOS enlarging the page when a user focuses an input with a font-size below 16px.

Commerce

Entitlement: An entitlement is a record that a specific account may access a specific artefact.
Merchant of record: A merchant of record is the legal seller of a transaction, responsible for collecting and remitting sales tax.
Webhook idempotency: Webhook idempotency is ensuring a replayed webhook produces no additional side effects.

Sequencing

Impact score: An impact score is an estimate, from 1 to 5, of how much a check affects organic outcomes.
Return on effort: Return on effort is impact divided by a weighted effort estimate, used to order work.
Sequencing: Sequencing is deciding what to build first when time is limited.