Antiquated HTML Snippets and Artefacts

With ever-changing devices, browsers, operating systems, form factors, specifications, personal preferences, tooling, and corporate interests, the web is in a constant state of flux. As a result, so is the HTML we write. For every line of the HTML specification itself that has changed since the language’s inception, there are many more bits of HTML that have seen what I’ll call ‘environmental’ changes. Adaptations to differing browsers, extensions, integrations, and systems which we find HTML existing in.

This article doesn’t cover once-specced but now obsolete bits of HTML but instead looks at all the snippets that have wormed their way into websites as result of, or in combat against, third-party integrations, browser competition, vendor extensions, and platform-specific hacks. The bits of HTML that were included for reasons, and which have been forgotten for present irrelevance. The snippets that live on only in the markup of sites from bygone eras and in the minds of those who fought during the browser wars.

X-UA-Compatible

<meta http-equiv="X-UA-Compatible" content="IE=edge">

In an age where browsers changed quickly and version-specific behaviours weren’t unheard of, it was deemed necessary to signal compatibility with specific versions of browsers with the X-UA-Compatible meta tag. Here the content attribute reads IE=edge, meaning that the target is the highest supported document mode in Internet Explorer (IE).

As outlined in the documentation, there are other values than edge. One can also supply a value of 5 through 11 to correspond with the associated Internet Explorer version, or EmulateIE7 through EmulateIE11 to enter into that version’s mode, but only if a valid DOCTYPE is declared, otherwise falling back to quirks mode.

<meta http-equiv="X-UA-Compatible" content="chrome=1">

Before Chrome took over the market, Google released an Internet Explorer plugin called Google Chrome Frame. Installable in Internet Explorer versions 6 through 9, it rendered websites in Chrome’s modified WebKit engine rather than Internet Explorer’s Trident engine if they had the tag set.

<meta http-equiv="X-UA-Compatible" content="requiresActiveX=true">

requiresActiveX was used to prompt Internet Explorer 10 to switch to desktop mode if in Metro mode, which didn’t support plugins.

ICBM Coordinate

<meta name="ICBM" content="-31.9548, 115.8602">

ICBM (an abbreviation of ‘intercontinental ballistic missile’) is hacker slang for one’s geographical location that dates back to Usenet days. The meta tag was used for identifying the location of a website’s subject and was referenced by the service GeoURL for plotting sites on the globe and helping people find sites of geographical proximity.

In an era where browsers changed regularly and the vicious browser wars were in full force, it was sometimes important to target a specific browser or version of one. Microsoft handled this in Internet Explorer with specially formatted comments as seen in the snippet. There were a number of operators that could be used to further refine the condition:

Netscape had its own way of handling conditional comments using JavaScript entities immediately following an opening comment tag. If evaluated to true, the comment would be included. If false, it’d just be a comment. Browsers other than Netscape would always treat it as just a comment.

<meta name="MSSmartTagsPreventParsing" content="TRUE">

Smart Tags was a system Microsoft introduced in Internet Explorer 6 which would automatically inject hyperlinks into pages. ^{An example given by Microsoft was that ‘a Smart Tag might detect the names of major companies on the Web and tag them, allowing you to access stock quotes and company information.’. Site owners were outraged, and the MSSmartTagsPreventParsing meta tag was introduced to allow opting out. Microsoft later dropped it from Internet Explorer entirely.}

PICS

<meta
	http-equiv="PICS-Label"
	content='
 (PICS-1.1 "http://www.gcf.org/v2.5"
    labels on "1994.11.05T08:15-0500"
           until "1995.12.31T23:59-0000"
           for "http://w3.org/PICS/Overview.html"
    ratings (suds 0.5 density 0 color/hue 1))
'
>

In the mid-90s the World Wide Web Consortium (W3C) attempted to establish a set of technical specifications for labelling internet content, called Platform for Internet Content Selection (PICS). PICS was incorporated into many filtering products, as well as Internet Explorer as of version 3. The shown meta tag could be included on a page to label it.

Rather unsurprisingly, many site owners just lied and miscategorised their sites. More still just never added the tags. The Protocol for Web Description Resources (POWDER) succeeded PICS but was also unsuccessful in its intentions. PICS was more or less completely dropped by 2003.

Interpage Transitions

<meta http-equiv="Page-Enter" content="revealTrans(Duration=2.0,Transition=12)">
<meta http-equiv="Page-Exit" content="revealTrans(Duration=2.0,Transition=12)">

Much like slide deck applications such as Microsoft PowerPoint or Apple Keynote have the ability to set transitions, Internet Explorer from version 4 to version 8 supported the above tags for transition style effects. This feature wouldn’t officially reach the web platform until the adoption of the View Transition API. Web developer Bramus has ported Internet Explorer’s transitions to the new View Transition API.

Frame Buster

<meta http-equiv="Window-target" content="_top">

Starting in Netscape Navigator in the mid-90s and then working its way over to Internet Explorer and other browsers, this non-standard meta tag would cause a page to break free of the parent page and open as a standalone browser window if it was loaded in a frame. It was popularly used by people to stop their pages from being embedded in frames on other sites. The _top Window-target specifies that a page should load in a top level window. In the modern age people use security headers to prevent pages from being embedded.

Baidu Page Transcoding

<meta name="applicable-device" content="pc,mobile">
<meta http-equiv="Cache-Control" content="no-siteapp,no-transform">

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

<meta name="skype_toolbar" content="skype_toolbar_parser_compatible">

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 attempt to detect phone numbers on pages and show a clickable icon. This icon allowed calling a number via Skype, adding it to one’s Skype address book, and assorted other Skype-related functionality. In inserting an icon, it would often cause page breakages, so developers would include the above tag to disable it on their sites.

The extension was also extremely unstable in Firefox, to the extent that Mozilla explicitly blocked it in 2011.

<meta http-equiv="imagetoolbar" content="no">

Internet Explorer 6 added an Image Toolbar, which would appear over images and show buttons for actions such as saving or sharing an image. Developers naturally hated this intrusion on their site and could disable the functionality with the above meta tag.

ClearType

<meta http-equiv="cleartype" content="on">

ClearType is Microsoft’s system for improving the legibility of typography. This tag could be included on pages to make typography look better on low-resolution devices, namely those running Pocket Internet Explorer / Internet Explorer Mobile.

AJAX Crawling

<meta name="fragment" content="!">

Google previously didn’t run JavaScript when crawling pages, so sites which had AJAX-based content would not be indexed. This meta tag told Google’s crawler to request a page with the _escaped_fragment_ query parameter, which was expected to return a HTML version of the page’s contents. Google began recommending this approach in 2009 and stopped advising it in 2015.

Directory

<meta name="robots" content="noodp, noydir">

Web directories used to be immensely popular as a way for people to find content on the internet. Two of the most popular were Yahoo Directory and DMoz (named for the URL directory.mozilla.org). The directories would sometimes write their own titles and descriptions for sites, which would be used by some search engines. To signal to search engines that they should use the metadata provided on the page and not the metadata from the directories, developers would include the above meta tag. Both directories are defunct now, making this snippet irrelevant.

Web App Name

<meta name="application-name" content="App Title">

application-name was used by various web app implementations across various browsers before Progressive Web Apps (PWAs) became established. If missing, systems usually fell back to