Definitions beginning with R

307 redirect

HTTP temporary-redirect response directing a client to the Location address while preserving the request method and body.

Reference: MDN : 307 Temporary Redirect

In practice: exercise a synthetic POST in a test environment and check destination, method and absence of real effects.

308 redirect

HTTP permanent-redirect response directing a client to the Location address while preserving the request method and body.

Reference: MDN : 308 Permanent Redirect

In practice: confirm that the move is permanent and that handling of the preserved method matches the destination route’s contract.

RankBrain

Machine-learning system used by Google to help understand queries and organise results.

In practice: Focus the page on the reader’s need rather than an unverifiable algorithm hypothesis.

Ranking

Relative ordering of pages or content according to a search engine, platform or recommendation model.

In practice: Compare positions in a defined context and connect them to useful visits.

Ransomware

Malware that locks or encrypts data to demand a ransom. The attack may also steal data and threaten to publish it.

Reference: Cybermalveillance.gouv.fr · Rançongiciels · Source consulted 2026-10-31

In practice: prepare tested restoration and a reporting path before an incident.

Rate limit

Rule limiting requests over a period and scope, such as an account, key or other criterion. HTTP 429 can signal the limit, sometimes with Retry-After. Clients need appropriate retry handling; immediately repeating the same request can prolong failure rather than resolve it.

Reference: MDN : 429 Too Many Requests · Source consulted 2026-10-18

In practice: Document thresholds and retry signals so a legitimate client can slow down cleanly.

Reading order

Sequence in which page or document content is encountered, including by keyboard or assistive technology.

In practice: navigate without a mouse and compare the sequence with the visual layout.

Real User Monitoring

Real User Monitoring (RUM): measurement of performance and errors encountered during real visits. Results depend on the devices, networks, pages and visits actually represented in collection.

Reference: web.dev : Field measurement

Source consulted : web.dev : Lab and field data · 2026-10-10

In practice: group measurements by page and device without exposing individual visitor data.

Redirect 301

HTTP response indicating a permanent move to the address supplied by Location. Check destination and method; deleted pages should not all lead to an unrelated homepage. Check the final destination and possible loops. Redirecting an old record to the homepage does not guarantee that the visitor’s need remains satisfied.

Reference: MDN · Redirections in HTTP · Source consulted 2026-10-25

Source consulted : MDN · 2026-10-17

In practice: send an old page to a genuinely relevant destination, then check the status and avoid redirect chains.

Redirect 302

HTTP response indicating a temporary move to another address. Some clients may convert POST to GET; if the method must be preserved, examine the appropriate status. Document the temporary reason and check the intended return path. A redirect chain adds steps without making content equivalent.

Reference: MDN · Redirections in HTTP · Source consulted 2026-10-25

Source consulted : MDN · 2026-10-17

In practice: Choose a temporary redirect only if the old address is expected to become the destination again.

Redirect chain

Sequence of redirects before the final destination. Each step adds an exchange and can create a loop; use a relevant destination and update internal links too.

Source consulted : MDN · 2026-10-17

In practice: send each old URL directly to its final equivalent.

Referral traffic

Traffic attributed by an analytics tool to links from other websites under its collection and classification rules. The referral category depends on available source information and configured exclusions. It therefore does not necessarily capture every link followed or every person involved.

Reference: Google Analytics : Default channel groups · Source consulted 2026-10-18

In practice: examine referring domains and a known test journey. Check returns from a payment provider and relevant exclusions before treating them as new acquisition; a missing domain in a report does not prove that no visitors came from it.

Registrar

Organisation through which a domain is registered and managed. Registrar, DNS provider and hosting provider can differ; keep their responsibilities and access arrangements distinct.

Source consulted : ICANN · 2026-10-17

In practice: Check the domain holder, renewal date and transfer procedure.

Relational database

Database organizing information into tables connected by keys and queryable in a structured way.

In practice: Define relationships and constraints to prevent orphaned records.

Render-blocking resource

Resource whose processing delays a step required to display the page. Its effect depends on type, placement and loading mode. Reducing blocking must preserve essential styles and behaviours; a large resource does not necessarily block rendering in the same way.

Reference: MDN : Render-blocking · Source consulted 2026-10-18

In practice: Measure whether the resource actually blocks first useful content before changing its loading.

Rendering

Operations turning a document and styles into displayed pixels, including style calculation, layout, painting and compositing. A size change can trigger new layout work. Downloading files quickly therefore does not alone guarantee a responsive interface.

Reference: MDN : How browsers work · Source consulted 2026-10-18

In practice: Compare what the browser receives with what a person sees after loading.

Resource library

Organised collection of documents or tools presented by need with an entry to assess before opening.

In practice: help people choose a resource before offering the file.

Resource type

Format or use category, such as template, guide or checklist, used to identify a document.

In practice: use types that the audience genuinely recognises.

Resource version

Dated state of a document distinguishing a current edition from a replaced copy.

In practice: remove or clearly label superseded copies.

Response time commitment

Stated period between receipt of an enquiry and a useful first reply. It needs a defined starting point, treatment of non-working periods and scope of requests.

In practice: state a response period the team can meet and review requests that exceed it.

Responsive design

Design that adapts layout, media and text to available space. Flexible grids alone are insufficient: also check navigation, long content and essential tasks at intermediate widths.

Reference: MDN : Responsive web design · Source consulted 2026-10-18

In practice: Check intermediate widths and zoom, not only one phone and one desktop size.

Responsive image

Image whose file or crop adapts to display context. Distinguish resolution selection from art direction: changing the crop is more than compressing the same file.

Reference: MDN : The picture element

Source consulted : MDN · 2026-10-17

In practice: check the variant actually served on a phone.

REST API

API designed around REST architectural constraints, including identifiable resources and stateless exchanges. Using JSON or HTTP alone does not establish that an API follows REST. HTTP methods and statuses should match the action. Do not assume that a read operation has no side effects from its URL shape alone.

Reference: MDN · REST · Source consulted 2026-10-25

Source consulted : MDN · 2026-10-17

In practice: Describe resources, statuses and errors with real request examples.

Retargeting

Advertising retargeting of people who previously visited a site or interacted with a brand, subject to consent rules.

In practice: Review reminder relevance, duration and opt-out before adding an audience.

Retrieval-Augmented Generation

Technique retrieving relevant external information before asking a model to generate an answer grounded in that context.

Reference: Microsoft Learn : Retrieval-Augmented Generation

In practice: Test retrieval of the right documents first, then answer fidelity to the retrieved passages.

Reverse proxy

Intermediary placed in front of servers to receive and forward requests. It can handle balancing, TLS or caching according to configuration. Addresses and forwarded headers must be interpreted within that chain; the application server may not see the original client directly.

Reference: MDN : Proxy servers and tunneling · Source consulted 2026-10-18

In practice: Check forwarded headers, actual URLs and caching in front of the application.

Rich result

Search result enhanced with additional presentation or information, often from eligible structured data.

In practice: Check format requirements and visible content; markup alone does not guarantee display.

robots.txt

File at a host’s root communicating crawl rules to supporting robots. It is neither access control nor a guarantee of removal from an index: links can still make a blocked URL known.

Reference: Google Search Central : robots.txt · Source consulted 2026-10-21

In practice: Test rules against the intended paths and remember they do not remove an already known URL.

ROI

Return on Investment: relationship between value obtained and resources committed to an action or project.

In practice: State time horizon, included costs and measured outcome before comparing investments.

Roles and permissions

Organisation of accessible actions and resources by profile and context. Permissions require server-side checks for each request and target object. A useful test compares two accounts and a resource owned by each; hiding the access button does not protect request handling.

Reference: OWASP : Authorization · Source consulted 2026-10-18

In practice: give writers, approvers and administrators only the permissions their tasks require.

Root domain

In common web and SEO usage, the registrable domain to which subdomains belong, such as example.co.uk for shop.example.co.uk. It cannot always be inferred from the final two labels. This usage differs from the technical DNS root at the top of the naming hierarchy.

Reference: Public Suffix List : Domain boundaries · Source consulted 2026-10-18

In practice: identify the registered domain, its holder and active subdomains before migration. A public suffix list helps locate the domain boundary; it does not establish purchase availability or ownership.

RSS

Syndication format allowing a reader or another website to automatically follow new publications from a source.

Reference: RSS Advisory Board : RSS 2.0

In practice: Check that the feed publishes durable URLs and dates matching real updates.