You can choose a Minimal Installation by de-selecting everything in the Package Group Selection screen, see la sezione chiamata «Selezione per gruppi di pacchetti».
Minimal Installation is intended for those with specific uses in mind for their Mageia, such as a server or a specialised workstation. You will probably use this option combined with Manual Package Selection, see la sezione chiamata «Scegli dei pacchetti individuali».
If you choose this installation class, then the related screen will offer you a few useful extras to install, such as documentation and X.