Spec fiction is that which was specified but never implemented.

A lot of my work is in web platform documentation, such as web-features (a structured catalog of browser capabilities) and MDN (the nearest thing to a canonical reference for HTML, CSS, JavaScript, and browser APIs). As a consequence, I read a lot of browser specifications (specs), to find out what browsers are supposed to do.

Since specs are written iteratively and often early in the development process, each spec reflects a mix of what ought to be and what is. Some years ago, I coined the term spec fiction to refer to things that exist in specs but do not actually exist any implementation and for which there is no evidence of an implementation in progress.

In case it’s not obvious, I meant this as a pun on the abbreviation for speculative fiction. And I can’t help but say it a little pejoratively. It’s (usually) too much to say that published browser specs lie, but they contain a great number of imaginary things. There are some specs that read more as wishlists than anything else (for example, CSS’s various print media features seem to have been specified far more extensively than implemented). But through some combination of ambition, optimism, changing priorities, and a reluctance to walk back agreed upon text, spec fiction persists.