UNIX systems are notorious for their treatment of 8-bit characters frequently used in PC environments. This issue directly affects the cross-boundary performance of systems relying on the 8th bit such as MLS which was originally designed for PCs. The main task of this extension is to render the vowel gender of a Mongol word. The latter is usually the case with contractions of verb roots and formerly free compounds. Only foreign loans contain free mixtures of male and female vowels.
Male vowels are unmarked.
MLS4UNIX follows the marking scheme but marks the whole word by prefixing it by an underscore. Long vowels are treated as single symbols. It is confessed that the appearance of this system seems to be a bit clumsy.