It sounds fancy, but it's nothing really–just the approaches I take in making steps. It's not a big, stupid guide like Phrek's, it just explains why things on Anarchy are the way they are.
Note that things became this way over time, and so things stated here may apply poorly to older files.
DDR is a “dancing game”. Ideally, then, a well-made DDR chart should incorporate at least basic aspects of dancing, because otherwise you're just playing a music game with your feet. Elements we view as critical are that dancing is a reaction to music, and does not necessitate prior familiarity with a particular song.
There is an unfortunately widespread tendency for simfile artists to create charts that fall in the “music game with feet” category–that is, you play notes directly as heard in the song, as if in stomping you play some kind of musical instrument. Nobody at a party dances like that, at least not without looking like a complete idiot (unless they actually have a musical instrument on the ground). This sort of design misses the point of the dancing game entirely (although if the file is intended for keyboard, this is not necessarily contradictory).
Anarchy files sync not directly to notes, but to the perceived flow of music. This creates a more natural feeling in-game, and makes it possible to connect the rest of your body (primarily arms) with your movements, as rhythms are fluid instead of choppy.
Pattern layouts primarily emphasize equal usage of each foot, and follow from there. Tiring out one leg over the other is rather unnatural, as is any dance skewed toward one side or the other.
Boss songs follow the same method of pattern layout, but are less dancelike in rhythm (though still reactionary as opposed to identical with the music, the distinction is more subtle). This is an inevitable consequence of the fact that high difficulty is not intentionally built into a dance, but often is intentional in DDR charts (as is often the case with challenge in games in general); as such, these charts emphasize the “game” character of DDR more than the “dancing” aspect.
Anarchy files are intended to be a sort of continuation to the DDR series after Extreme. That the actual series later diverged from this direction is irrelevant.
The difficulty scale used for Anarchy files is an extension of that seen in DDR Extreme, with songs from 1-9 lining up in both. Songs such as MAX 300 and SAKURA are used as a benchmark for 10, while The legend of MAX and PARANOiA Survivor MAX are representative of 11s (flashing 10 in Extreme).
The additional two difficulties (12 and 13) are in place because of files that are much more difficult than anything found in DDR Extreme. 12s could be roughly equated to SuperNOVA's Fascination MAXX, but the latter's poor pattern design inflates its difficulty significantly. It should be obvious through gameplay that 12s and 13s represent distinct levels from each other, and that they are significantly more difficult than 11s.