Antiquated HTML Snippets and Artefacts

<meta name="MSSmartTagsPreventParsing" content="TRUE"> Smart Tags was a system Microsoft introduced in Internet Explorer 6 which would automatically inject hyperlinks into pages.1 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.

`<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.

`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](https://learn.microsoft.com/en-us/previous-versions/windows/internet-explorer/ie-developer/platform-apis/ms532847(v=vs.85)#interpage-transitions). This feature wouldn’t officially reach the web platform until the adoption of the [View Transition API](https://developer.mozilla.org/en-US/docs/Web/API/View_Transition_API). Web developer Bramus has ported Internet Explorer’s [transitions to the new View Transition API](https://page-transitions.style).

<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.

`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](https://zzz.buzz/zh/2017/04/10/baidu-mobile-seo-and-baidu-siteapp/). 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.

<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.

<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.

<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.

`Internet Explorer 9 and higher on Windows 7 had a function to [pin sites to the taskbar](https://learn.microsoft.com/en-us/previous-versions/windows/internet-explorer/ie-developer/samples/gg491738(v=vs.85)). When pinned, sites could expose some site features on an operating system and browser level, almost like a modern progressive web app. `msapplication-tooltip` was text shown when hovering a site’s icon, `msapplication-starturl` set the root URL of the pinned site, `msapplication-window` set the initial size of the pinned site’s window when opened (minimum width of 800px and height of 600px), `msapplication-navbutton-color` set a custom colour for the browser chrome’s back and forward navigation buttons, and [`msapplication-task`](https://learn.microsoft.com/en-us/previous-versions/windows/internet-explorer/ie-developer/samples/gg491725(v=vs.85)#using-msapplication-task) was used to define quick actions which could be accessed by secondary clicking a pinned site in the taskbar. For example, a quick link to a blog page.

`Very similar to the previously mentioned Pinned Site functionality, these values were used for presentation. `msapplication-TileColor`, `msapplication-TileImage`, and the various `msapplication-square*` and `msapplication-wide*` attribute carrying tags were used for setting the theming of the tiles across the assorted versions of Windows, including the desktop UI, Metro UI, and Windows Mobile.

<meta name="application-url" content="https://vale.rocks"> Google Chrome had some pinned web app functionality which would use application-url for the start URL.

<link rel="mask-icon" href="icon.svg" color="green"> Pinned Sites/Tabs in Safari allowed ‘users to keep their favorite websites open, running, and easily accessible.’. An SVG icon for the Pinned Tab could be declared alongside a colour which the icon would use.

<link rel="chrome-application-definition" href="application_definition.json"> CRX-less Web Apps were applications in Google Chrome which allowed using an online manifest to describe a hosted app. The above meta tag would link to a JSON file with 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 be distributed on the Chrome Web Store with just the JSON manifest and an icon, with no need for the full .crx format Chrome uses for extensions. This type of app was later renamed to ‘Chrome Apps’, which are being phased out.

`To allow site owners to customise the experience of their websites when added to a user’s homescreen on iOS, Apple [introduced the above meta tags](https://developer.apple.com/library/archive/documentation/AppleApplications/Reference/SafariWebContent/ConfiguringWebApplications/ConfiguringWebApplications.html). The icon, startup image, and title are self-explanatory, while `apple-mobile-web-app-capable` disabled the browser chrome, and `apple-mobile-web-app-status-bar-style` allowed setting the operating system status bar to one of three possible values:

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

`UC Browser and QQ Browser were particularly popular browsers in Asia through the early to mid-2010s due to their heavy data savings and optimisation for cheap devices. UC Browser would use `screen-orientation` to force a specific display orientation and `full-screen` to hide the browser’s chrome. QQ Browser would do the same, though with `x5-orientation` and `x5-fullscreen`. ‘X5’ in those meta names refer to Tencent’s X5 browser engine. The meta tags are no longer needed due to the standard fullscreen and orientation APIs and popularisation of more capable browsers.

`Before the proliferation of `` for making sites cleanly scale to small screens, these tags were widely used for mobile content. `HandheldFriendly` was created for [AvantGo](https://getoutofmyhead.dev/handheld-friendly) and then [spread to the Blackberry Browser](https://web.archive.org/web/20150306230553/https://developer.blackberry.com/playbook/html5/documentation/handheldfriendly.html), while `MobileOptimized` was a [Microsoft concoction](https://learn.microsoft.com/en-us/previous-versions/bb431690(v=msdn.10)) for old versions of [Windows Mobile](https://vale.rocks/posts/pda-browsers#windows-mobile).

<meta name="msapplication-tap-highlight" content="no"> This snippet stops links from highlighting when tapped in Internet Explorer 11. It was similar to -webkit-tap-highlight-color, though unlike that property it was a boolean and didn’t allow changing the colour.

<meta name="revisit-after" content="7 days"> A website called Vancouver Webpages ran a niche regional search system called ‘searchBC’ (the BC standing for ‘British Columbia’) which used the tag to know how often it should re-scrape a site. However, this was the only known use of the tag. There is no evidence that it has ever been used by any major search engine, including Google. Despite this, it somehow caught on like some sort of SEO myth and was perpetuated across the web.

<link rel="prerender" href="https://example.com"> Only fully supported in Chrome between versions 13 and 62 and never specced, this would fetch and process a page so it would be ready when users navigate to it. The functionality was replaced by the Speculation Rules API.

<link rel="amphtml" href="https://example.com/amp.html"> Accelerated Mobile Pages (AMP) were restructured versions of pages optimised for faster content loading. This tag was used to link to an AMP version of a page, however, Accelerated Mobile Pages are no longer widely used, and Google no longer pushes for them, making the tag unneeded.

<meta name="IE_RM_OFF" content="true"> Starting with Internet Explorer 9, ‘Reading View’ was introduced. By pressing a button which would appear in the browser chrome, you could get a simplified version of a page suited for reading. Pages could opt out of having this button shown by including the aforementioned meta tag.