Here's a short explanation of what the various tags means.
100% Noisetracker / Protracker compatible
Indicates that the MOD file is kept within Noisetracker / Protracker contraints.
Available in other bitrates and frequencies
When marking tracks with this tag, the artist indicates that the game-developer can easily get his hands on another version of the track, either in a higher og lower quality.
Used to mark the file as being chip music. It may be e.g. a MOD or XM using chip sounds, but can also be an MP3 or OGG file with chip instruments (e.g. a rendering of an XM).
Finally, it can also be a MIDI+soundfont package, where the soundfont file contains chip-instruments.
Comes with Elias XML
Used for building block tracks to tell the game-developer that the building blocks comes with an XML file to be used in the Elias Engine from Elias Software.
Providing this XML file is just an additional service the artist chooses to give. It's entirely up to the game-developer whether he wishes to use the Elias Engine or not.
Music has an ending (Doesn't loop)
This tag means that the track either fades out or else has an ending that clearly indicates that the track is over.
Tracks marked with this tag are not suitable for looping.
Music is loop-able, but also has an ending
This tag tells that the track can be looped, but it doesn't have to be looped.
This is achieved by giving the track an ending combined with a timing. For example, the track could end with some drums that provides a break in the track, so that a pause comes naturally - whereafter the track restarts, giving an impression of a loop.
This technique was used a lot on the old JavaME platform, because the platform technically just can't perform a smooth loop.
It can also be used for the mp3 format, which technically can't do a smooth loop either.
Music requires/does smooth looping
Tracks marked with this tag requires to be looped smoothly, in order for it to sound fine. Minor gaps between plays will ruin the music.
Because of this requirement, there are certain file-types you'll never see marked with this tag. MP3 for example, technically can't be played in a smoothly looping state.
You will find OGG, FLAC and WAV files marked with this tag. And tracker formats can also be marked with this tag, typically to indicate that the track automatically loops to a previous pattern at the end of the track.
Optimized for JavaME
Used to mark a MIDI as being optimized for filesize and compability on the JavaME platform (mobile games). Genereally this means the MIDI will be in SMF0 format, and usually very small in filesize.