The Eviscerate Only cycle indicates that with the gear and spec you have entered, the optimal cycle uses only Slice and Dice and Eviscerate – no Ruptures. In general, this cycle consists of 5pt Eviscerates alternating with Slice and Dice as needed. Slice and Dice is refreshed with 5 combo points if you can pool within n seconds of SnD dropping; otherwise, it is refreshed with whatever combo points you have as the previous Slice and Dice is dropping.
Low Rupture is a 3 finisher cycle – SnD, Evis, and Rupture – which prioritizes efficient combo point usage. In practice, this is functionally identical to Eviscerate Only, except that instead of Eviscerating whenever you have 5 CP and don't need to refresh SnD, you Rupture if it's down and Eviscerate otherwise. All timings in terms of Slice and Dice are identical.
High Rupture is a 3 finisher in cycle, though in practice you will very seldom use Eviscerate. The priority of this cycle is 100% SnD uptime and maximal rupture uptime, Eviscerating only as much as is possible without compromising these goals. This is generally done by performing a small (usually 3-4 point) SnD, then building combo points until there are m seconds left on the previous Rupture, performing an Eviscerate if one has at least 2 combo points, and then building 5 combo points for the next Rupture. In conventional cycle notation, this would be something like 3s[2+e]5r. Note that the Slice and Dice will frequently be refreshed with a number of seconds remaining; it is absolutely essential that the SnD be large enough to last until the next one can be performed, with a rupture in between. Thus, one must err on the side of having it be a bit too big, rather than exactly the right length to avoid wasting uptime.