favicon

Browser tab icon, defaulting to favicon.ico.

The <link> is what makes an icon at the output root reachable at all: a browser's implicit favicon request always goes to the origin root, which on a project site published under a path prefix is not where your decks are. A relative value resolves against the output root, so one path works from a deck at any depth; absolute (/img/icon.png), external (https://...), and data: values pass through. Supply the file at the output root for filesystem output, or on the classpath under com.kslides.config.OutputConfig.defaultHttpRoot for HTTP.

Blank omits the <link> element. kslides ships no icon, so set this blank if your site has none rather than asking every page for a file that is not there.