Living collection · HED-001 to HED-024
What the document says about itself without showing, one star per page.
Everything in the <head> is invisible on the page, like a sky nobody looks at: each element is a star that only appears through an instrument. Every one gets its card, its label, and the answer to the question that matters — how to invoke it.
Drawers
The five drawers these stars are filed in.
The whole sky
- HED-001 <link rel="preconnect"> Opens the connection to another origin before the first request — DNS, TCP and TLS paid up front. Connections common
- HED-002 <link rel="dns-prefetch"> Only the first leg of the trip: it resolves the server's name and stops there. Connections uncommon
- HED-003 <link rel="preload"> Orders a resource for this page before the parser finds out it needs it. Connections common
- HED-004 <link rel="prefetch"> Fetches, at low priority, something the next navigation will probably want. Connections uncommon
- HED-005 <link rel="modulepreload"> The preload that speaks module: it fetches, parses and compiles in one go. Connections uncommon
- HED-006 <link rel="canonical"> Declares which address is the official one when the same page answers to several. Identity common
- HED-007 <link rel="alternate" hreflang> Introduces the page's editions in other languages — itself included. Identity uncommon
- HED-008 <link rel="alternate" type="application/rss+xml"> The feed readers' discovery door, open since before social networks. Identity forgotten
- HED-009 <link rel="me"> Identity verification without signup: two links pointing at each other. Identity forgotten
- HED-010 <link rel="license"> Points at the main content's license, where machines can read it. Identity forgotten
- HED-011 <link rel="author"> Links the document to whoever wrote it — a page about the person, or an email address. Identity forgotten
- HED-012 <meta name="color-scheme"> Announces which color schemes the page knows how to behave in — before the CSS arrives. Appearance uncommon
- HED-013 <meta name="theme-color"> Paints the browser around the page — the frame, not the painting. Appearance uncommon
- HED-014 <link rel="icon"> The document's portrait on the tab, in bookmarks and in search results. Appearance common
- HED-015 <link rel="apple-touch-icon"> The iPhone home-screen icon — the Apple extension everybody adopts. Appearance common
- HED-016 <link rel="manifest"> Points at the manifest that teaches the page to behave like an app. Appearance uncommon
- HED-017 <meta name="viewport"> The pact with the small screen: without it, the phone pretends to be a 980-pixel desktop. Behavior common
- HED-018 <meta name="referrer"> Decides how much of your address travels along when someone leaves the page. Behavior uncommon
- HED-019 <meta name="robots"> A request for discretion to the indexers — which the polite ones honor. Behavior common
- HED-020 <meta http-equiv="refresh"> Reloads or redirects on its own, counting the seconds at the top of the document. Behavior forgotten
- HED-021 <base href> Changes the ruler for every relative address in the document — every single one. Behavior forgotten
- HED-022 <meta name="format-detection"> Stops Safari from turning every phone-looking number into a blue link. Behavior forgotten
- HED-023 <script type="speculationrules"> The only script that runs no code of yours: JSON authorizing the browser to bet. Speculation uncommon
- HED-024 <link rel="prev"> The stitching between the pages of a series — retired by Google, not by readers. Speculation forgotten