Antiquated HTML Snippets and Artefacts

Sep 08, 2026 04:43 PM - 1 hour ago 4

With ever-changing devices, browsers, operating systems, shape factors, specifications, individual preferences, tooling, and firm interests, the web is successful a changeless authorities of flux. As a result, truthful is the HTML we write. For each statement of the HTML specification itself that has changed since the language’s inception, location are galore much bits of HTML that person seen what I’ll telephone ‘environmental’ changes. Adaptations to differing browsers, extensions, integrations, and systems which we find HTML existing in.

This article doesn’t screen once-specced but now obsolete bits of HTML but alternatively looks astatine each the snippets that person wormed their measurement into websites arsenic consequence of, aliases successful combat against, third-party integrations, browser competition, vendor extensions, and platform-specific hacks. The bits of HTML that were included for reasons, and which person been forgotten for coming irrelevance. The snippets that unrecorded connected only successful the markup of sites from bygone eras and successful the minds of those who fought during the browser wars.

X-UA-Compatible

In an property wherever browsers changed quickly and version-specific behaviours weren’t unheard of, it was deemed basal to awesome compatibility pinch circumstantial versions of browsers pinch the X-UA-Compatible meta tag. Here the contented property sounds IE=edge, meaning that the target is the highest supported archive mode successful Internet Explorer (IE).

As outlined successful the documentation, location are different values than edge. One tin besides proviso a worth of 5 done 11 to correspond pinch the associated Internet Explorer version, aliases EmulateIE7 done EmulateIE11 to participate into that version’s mode, but only if a valid DOCTYPE is declared, different falling backmost to quirks mode.

Before Chrome took complete the market, Google released an Internet Explorer plugin called Google Chrome Frame. Installable successful Internet Explorer versions 6 done 9, it rendered websites successful Chrome’s modified WebKit motor alternatively than Internet Explorer’s Trident motor if they had the tag set.

requiresActiveX was utilized to punctual Internet Explorer 10 to move to desktop mode if successful Metro mode, which didn’t support plugins.

ICBM Coordinate

ICBM (an abbreviation of ‘intercontinental ballistic missile’) is hacker slang for one’s geographical location that dates backmost to Usenet days. The meta tag was utilized for identifying the location of a website’s taxable and was referenced by the work GeoURL for plotting sites connected the globe and helping group find sites of geographical proximity.

In an era wherever browsers changed regularly and the vicious browser wars were successful afloat force, it was sometimes important to target a circumstantial browser aliases type of one. Microsoft handled this successful Internet Explorer pinch specially formatted comments arsenic seen successful the snippet. There were a number of operators that could beryllium utilized to further refine the condition:

Operator Description

IE	Denotes Internet Explorer. Can besides see a version, specified arsenic IE 7.
lt	Less than.
lte	Less than aliases equal.
gt	Greater than.
gte	Greater than aliases equal.
!	NOT.
&	AND.
\|	OR.
()	Subexpression operator.
true	Always evaluates to true.
false	Always evaluates to false.

Netscape had its ain measurement of handling conditional comments utilizing JavaScript entities instantly pursuing an opening remark tag. If evaluated to true, the remark would beryllium included. If false, it’d conscionable beryllium a comment. Browsers different than Netscape would ever dainty it arsenic conscionable a comment.

Smart Tags was a strategy Microsoft introduced successful Internet Explorer 6 which would automatically inject hyperlinks into pages.1 An illustration fixed by Microsoft was that ‘a Smart Tag mightiness observe the names of awesome companies connected the Web and tag them, allowing you to entree banal quotes and institution information.’. Site owners were outraged, and the MSSmartTagsPreventParsing meta tag was introduced to let opting out. Microsoft later dropped it from Internet Explorer entirely.

PICS

In the mid-90s the World Wide Web Consortium (W3C) attempted to found a group of method specifications for labelling net content, called Platform for Internet Content Selection (PICS). PICS was incorporated into galore filtering products, arsenic good arsenic Internet Explorer arsenic of type 3. The shown meta tag could beryllium included connected a page to explanation it.

Rather unsurprisingly, galore tract owners conscionable lied and miscategorised their sites. More still conscionable ne'er added the tags. The Protocol for Web Description Resources (POWDER) succeeded PICS but was besides unsuccessful successful its intentions. PICS was much aliases little wholly dropped by 2003.

Interpage Transitions

Much for illustration descent platform applications specified arsenic Microsoft PowerPoint aliases Apple Keynote person the expertise to group transitions, Internet Explorer from type 4 to type 8 supported the supra tags for modulation style effects. This characteristic wouldn’t officially scope the web level until the take of the View Transition API. Web developer Bramus has ported Internet Explorer’s transitions to the caller View Transition API.

Frame Buster

Starting successful Netscape Navigator successful the mid-90s and past moving its measurement complete to Internet Explorer and different browsers, this non-standard meta tag would origin a page to break free of the genitor page and unfastened arsenic a standalone browser model if it was loaded successful a frame. It was popularly utilized by group to extremity their pages from being embedded successful frames connected different sites. The _top Window-target specifies that a page should load successful a top level window. In the modern property group usage information headers to forestall pages from being embedded.

Baidu Page Transcoding

The Baidu Browser (百bǎi度dù浏liú览lǎn器qì) included a page ‘transcoding’ characteristic connected mobile which was immensely unpopular. Websites would beryllium routed done transcoder.baidu.com and modified. Layouts would beryllium restructured, styles stripped, images compressed, branding removed, and adverts connected the tract would beryllium removed while Baidu Union (百bǎi度dù联lián盟méng) adverts would beryllium injected. It heavily disrupted sites. One of these tags would beryllium added to sites from 2012 done to 2018 to opt retired of this transcoding taking place.

There was an add-on for Internet Explorer, Chrome, and Firefox called ‘Skype Toolbar’ (later ‘Skype Click to Call’). Available from the mid-2000s until the mid-2010s, it was automatically installed alongside Skype and would effort to observe telephone numbers connected pages and show a clickable icon. This icon allowed calling a number via Skype, adding it to one’s Skype reside book, and type different Skype-related functionality. In inserting an icon, it would often origin page breakages, truthful developers would see the supra tag to disable it connected their sites.

The hold was besides highly unstable successful Firefox, to the grade that Mozilla explicitly blocked it successful 2011.

Internet Explorer 6 added an Image Toolbar, which would look complete images and show buttons for actions specified arsenic redeeming aliases sharing an image. Developers people hated this intrusion connected their tract and could disable the functionality pinch the supra meta tag.

ClearType

ClearType is Microsoft’s strategy for improving the legibility of typography. This tag could beryllium included connected pages to make typography look amended connected low-resolution devices, namely those moving Pocket Internet Explorer / Internet Explorer Mobile.

AJAX Crawling

Google antecedently didn’t tally JavaScript erstwhile crawling pages, truthful sites which had AJAX-based contented would not beryllium indexed. This meta tag told Google’s crawler to petition a page pinch the _escaped_fragment_ query parameter, which was expected to return a HTML type of the page’s contents. Google began recommending this attack successful 2009 and stopped advising it successful 2015.

Web App Name

application-name was utilized by various web app implementations crossed various browsers earlier Progressive Web Apps (PWAs) became established. If missing, systems usually fell backmost to <title>.

Internet Explorer Pinned Sites

Internet Explorer 9 and higher connected Windows 7 had a usability to pin sites to the taskbar. When pinned, sites could expose immoderate tract features connected an operating strategy and browser level, almost for illustration a modern progressive web app. msapplication-tooltip was matter shown erstwhile hovering a site’s icon, msapplication-starturl group the guidelines URL of the pinned site, msapplication-window group the first size of the pinned site’s model erstwhile opened (minimum width of 800px and tallness of 600px), msapplication-navbutton-color group a civilization colour for the browser chrome’s backmost and guardant navigation buttons, and msapplication-task was utilized to specify speedy actions which could beryllium accessed by secondary clicking a pinned tract successful the taskbar. For example, a speedy nexus to a blog page.

Microsoft Web Apps

Very akin to the antecedently mentioned Pinned Site functionality, these values were utilized for presentation. msapplication-TileColor, msapplication-TileImage, and the various msapplication-square* and msapplication-wide* property carrying tags were utilized for mounting the theming of the tiles crossed the type versions of Windows, including the desktop UI, Metro UI, and Windows Mobile.

msapplication-badge was utilized to specify a web reside to beryllium polled for notifications which would show connected a site’s Live Tile.

Chrome Pinned Web Apps

Google Chrome had immoderate pinned web app functionality which would usage application-url for the commencement URL.

CRX-less Web Apps

CRX-less Web Apps were applications successful Google Chrome which allowed utilizing an online manifest to picture a hosted app. The supra meta tag would nexus to a JSON record pinch the manifest:

{ "name": "Application", "description": "Description describing the app.", "launch_url": "index.html", "launch_container": "panel", "icons": { "128": "128.png" }, "permissions": ["notifications"] }

These CRX-less apps could beryllium distributed connected the Chrome Web Store pinch conscionable the JSON manifest and an icon, pinch nary request for the afloat .crx format Chrome uses for extensions. This type of app was later renamed to ‘Chrome Apps’, which are being phased out.

iOS Web Apps

To let tract owners to customise the acquisition of their websites erstwhile added to a user’s homescreen connected iOS, Apple introduced the supra meta tags. The icon, startup image, and title are self-explanatory, while apple-mobile-web-app-capable abnormal the browser chrome, and apple-mobile-web-app-status-bar-style allowed mounting the operating strategy position barroom to 1 of 3 imaginable values:

default - White inheritance pinch achromatic matter and icons.
black - Black inheritance pinch achromatic matter and icons.
black-translucent - Background colour originated from the webpage inheritance colour pinch achromatic matter and icons.

These meta tags are now rendered obsolete by modern PWA definitions.

apple-touch-fullscreen was utilized successful immoderate early demos for iOS 2, however, Apple’s archiving only reflects apple-mobile-web-app-capable. Due to its beingness successful those early demos, apple-touch-fullscreen was popularised earlier the characteristic released, seemingly prompting Apple to make it an othername of apple-mobile-web-app-capable.

UC Browser and QQ Browser

UC Browser and QQ Browser were peculiarly celebrated browsers successful Asia done the early to mid-2010s owed to their dense information savings and optimisation for inexpensive devices. UC Browser would usage screen-orientation to unit a circumstantial show predisposition and full-screen to hide the browser’s chrome. QQ Browser would do the same, though pinch x5-orientation and x5-fullscreen. ‘X5’ successful those meta names mention to Tencent’s X5 browser engine. The meta tags are nary longer needed owed to the modular fullscreen and predisposition APIs and popularisation of much tin browsers.

PDA Optimised

Before the proliferation of <meta name="viewport" content="width=device-width"> for making sites cleanly standard to mini screens, these tags were wide utilized for mobile content. HandheldFriendly was created for AvantGo and past spread to the Blackberry Browser, while MobileOptimized was a Microsoft concoction for aged versions of Windows Mobile.

Internet Explorer Tap Highlight

This snippet stops links from highlighting erstwhile tapped successful Internet Explorer 11. It was akin to -webkit-tap-highlight-color, though dissimilar that spot it was a boolean and didn’t let changing the colour.

Revisit-After

A website called Vancouver Webpages ran a niche location hunt strategy called ‘searchBC’ (the BC opinionated for ‘British Columbia’) which utilized the tag to cognize really often it should re-scrape a site. However, this was the only known usage of the tag. There is nary grounds that it has ever been utilized by immoderate awesome hunt engine, including Google. Despite this, it someway caught connected for illustration immoderate benignant of SEO story and was perpetuated crossed the web.

Page Prerendering

Only afloat supported successful Chrome betwixt versions 13 and 62 and ne'er specced, this would fetch and process a page truthful it would beryllium fresh erstwhile users navigate to it. The functionality was replaced by the Speculation Rules API.

Accelerated Mobile Pages Version

Accelerated Mobile Pages (AMP) were restructured versions of pages optimised for faster contented loading. This tag was utilized to nexus to an AMP type of a page, however, Accelerated Mobile Pages are nary longer wide used, and Google nary longer pushes for them, making the tag unneeded.

Internet Explorer Reading View

Starting pinch Internet Explorer 9, ‘Reading View’ was introduced. By pressing a fastener which would look successful the browser chrome, you could get a simplified type of a page suited for reading. Pages could opt retired of having this fastener shown by including the aforementioned meta tag.

Really Simple Discovery

Really Simple Discovery (RSD) was a strategy for exposing services for managing a blog to clients. The nexus successful the caput would nonstop clients to an XML archive which would see endpoints to which devices specified arsenic Windows Live Writer, BlogJet, aliases MarsEdit could connect. It was implemented crossed platforms, including WordPress, Blogger, LiveJournal, TypePad, and MediaWiki. Modern publishing systems person mostly deprecated it.

Pingbacks

Pingbacks were a strategy wherever sites would alert different sites erstwhile they linked to them. The tract receiving the ‘ping’ would cheque that a nexus was really coming connected the tract sending the ping, past make a statement connected the page saying thing to the effect of ‘[Website] linked to this page’. They functioned somewhat likewise to really WebMentions do.

Unfortunately, pingbacks alternatively quickly became an avenue for spam and SEO-gaming, truthful fell retired of fashion. Vulnerabilities allowing sites to beryllium tied up successful DDoS attacks besides became wide exploited.

Before Facebook created Open Graph, they had a ‘Share Partners’ strategy for defining metadata to beryllium utilized successful embeds. Many further sites adopted it arsenic an advertisement hoc modular and implemented the tags. For example, Digg.

rel="image_src" would beryllium referenced for an image to embed, rel="audio_src" would beryllium referenced for audio to embed, and likewise rel="video_src" for video. There were a number of these meta tags which were supported to varying degrees.

Twitter Embeds

These meta tags (and immoderate other, little often utilized ones) were utilized connected Twitter erstwhile generating nexus embeds. However, the archiving and paper validator are nary longer accessible (previously astatine https://dev.twitter.com/cards/getting-started and https://cards-dev.twitter.com/validator respectively). X falls backmost to the wide respected Open Graph meta tags, making the Twitter-specific declarations mostly useless. They should beryllium removed successful favour of Open Graph tags. Further, they should beryllium removed because X is an atrocious tract pinch mediocre moderation that is owned by a man who publically performed a Nazi Sieg Heil salute and has straight contributed to the emergence of fascism successful the United States of America and globally, among different horrors.

Twitter besides had a Do Not Track meta tag for opting retired of search erstwhile utilizing Twitter for Websites widgets. Again, the archiving (previously astatine https://dev.twitter.com/web/overview/privacy) is now inaccessible, and it seems the tag is nary longer respected.

This article isn’t comprehensive. These are only the much celebrated aliases notable non-standard bits. There are truthful galore much obscure bits drifting done the shatters of cyberspace. For the funny mind, immoderate much are listed – albeit without associated item – connected the WhatWG Wiki.