Parts of the Web stack are supported by browsers but not specified by standards. Needless to say, this hurts interoperability.

The goal of this document is to gather pieces of the Web stack that developers know can be useful but that aren't specified in an interoperable manner.

Features that are eligible should be supported by more than one browser, even if perhaps differently between browsers. If you feel that a given browser sports a particularly important yet unspecified feature but is the only implementation for it feel free to make the case for it.

Please note that this is not a document in which to list features you would like to see on the Web but aren't available in any implementation. For that, we recommend that you discuss the matter in Discourse.

Discussion is open to all. If you would like to add some content, please make a pull requests (just follow the way in which the rest of the HTML is structured). If you are unsure, or just want to signal a problem, just file an issue.

Markup

This section is for unspecified features to do with HTML, SVG, or MathML as languages.

CSS

This section is for unspecified features to do with styling.

APIs

This section is for unspecified features to do with APIs and scripting in general.

window.find()

This method finds a string in the DOM in the same way that the browser’s find functionality does. Its design is somewhat horrible but it is used by actual libraries and code in the wild.

There is some documentation on MDN, as well as an interesting bug on the topic. IE has it as findText().

This should:

  1. Be specified sufficiently to be interoperable and work with existing content.
  2. Be complemented with a more modern API able to find Ranges based on a search string.

console

The console object is universally supported but is not specified.

The case has been made before that this is a developer-oriented feature that has no direct effect for most end users, and can thus go unspecified. It is safe to say that developers might not necessarily agree that it is wonderful for a content-exposed feature to lack interoperability.

File Save As

This issue was raised by Florian Bösch in the p-w mailing list recently. The following discussion indicated that these APIs have been implemented or will be implemented by the vendors but haven't got carefully designed yet.

These APIs should be clarified in the FileSystem API if possible.

Graphics

This section is for unspecified features to do with (primarily raster) graphics.

Cursor formats

The formats widely implemented for custom cursors (Microsoft .cur format, the related .ico and .ani) are only documented by a 1995 MSDN article and some blog posts.

Animated PNG

The animated PNG proposal was rejected by the PNG development group and never became part of the official specification. It is however implemented in some browsers, and is useful. The tooling situation has also improved. Regularising the standards status would be a benefit.

Miscellaneous

This section is for unspecified features that fit nowhere else.