Every version of the logo, shown on the ground it is made for, with its files: SVG for any size, PNG with a transparent background.
Rules
Where it goes and how big: logo. All files and how they are rebuilt: system/logo/.
Colourways
Colour on white, paper or pale yellow. Colour, dark (white bird and name) on night and dark photographs. Black and white where colour fights the page; both also work on the logo red. Red on light grounds.
Mark and name
The horizontal lockup is the main logo. The others are for spaces it doesn't fit.
Horizontal · the main logo: header, letterhead, email signature
The same full mark, drawn for each size, shown at real size. Use these for avatars and icons rather than shrinking the big file. Each size links to its PNG; @2x files (up to 128 px) are in the same folder. Favicon: favicon.ico.