This manual is on the web where it can be searched:
In the Menu item “About”, under “Online Docs URL...” there is a entry bar that can be used to search the Coot documentation via Google. The results are returned as a web page in web browser. The browser type can be specified as in this example:
(set-browser-interface "firefox")
Example usage can be found in xxx/share/coot/scheme/group-settings.scm