I've made cleanup in Gammu documentation and the only place where to look for it is now The Gammu Manual. Reason for this is simple - single documentation format allows easy cross-referencing and is easier to maintain than mixed sources we used to have before. Thanks to using Sphinx it is possible to generate various outputs, you can see the HTML version on the website, you can download PDF variants and the same source is being used for generating man pages.
PS: You can find more details on generating other formats in the documentation.
