The Qotsisajak, or the Sith Code. It was created by Sorzus Syn, one of the Dark Jedi exiles that found their way to Korriban after the Battle of Corbos.
In Basic, it is as follows.
Peace is a lie, there is only passion.
Through passion, I gain strength.
Through strength, I gain power.
Through power, I gain victory.
Through victory, my chains are broken.
The Force shall free me.
Like the two Jedi codes, it is a victim of contention with it's cleverly disguised message and the thinly veiled poking at the Jedi Code.
Peace is a lie. This segment is a reference to the nature of all things. When it comes down to the bare bones of life, all things kill. Every being older than a year has killed at least once, whether it be a plant, an insect, or anything domesticated. Sentients also feel emotions, from the strongest of the Sith to the most controlled of the Jedi. No amount of control can take away one's pride, nor their heart.
Emotions, however, cause conflict. Take the forbidden relationship of Senator Padmé Amidala and the Jedi Knight Anakin Skywalker, for instance. It was because the young, sheltered Anakin met her on Tatooine that he obsessed over her for the rest of his life as a Jedi, and suffered for his entire life as a Sith. He lusted after a woman out of his reach by his own code. This caused a dissonance between him, his Order, and his master. Eventually, he became frustrated and that frustration became rage. That rage, mixed with his lust and obsession, is what made him so malleable to Darth Sidious.
Another anecdote would be one of two kings falling for the same woman.
Rival kings King Richard and King George both have fallen for the maiden Melina. Neither knows about the other, until they run into one another in the marketplace. They go to war over Melina's hand. Love once again causes war.
This leads us to the second half of the first line.
There is only passion. Passion is not necessarily an emotion. It can be anything you feel strong enough about. Getting caught up in the moment is meditation enough to find the Force sometimes.
If one loves strong enough, you can use the Dark Side of the Force just as powerfully as somebody using hatred. They would have an easier time of it, but it's certainly possible. Even a strong religious zeal is enough to spark the channelling of Dark Side energy.
Through passion, I gain strength. Emotions mix oddly with the Force, both inside us and around us. Fear sparks the Human body to produce adrenaline, making the body stronger and faster. The Dark Side is adrenaline, and passion is the catalyst. It's really quite simple.
Through strength, I gain power. This one is pretty self-explanatory. The stronger anything you have is, the more power you can wield. It's why a physically fit man could lift something that a man that has never exercised once cannot. This is the same for the mind and the will. Strength can be any number of things, though, as can power. Strength could be money, and wealth is a power of it's own. The smarter you are, the more you can outsmart others.
Through power, I gain victory. Again, this is pretty self-explanatory. The more powerful one is, the less they can be defeated in any way. However, as a rule of thumb, never assume you are the most powerful. Always assume there is another, more powerful than you, and another more powerful than them, and so on and so forth.
Through victory, my chains are broken. Chains is being used as a placeholder for restraints here. By being victorious in battle against your own doubts, you rid yourself of a chain that could hold you back for a very long time. When you win a battle against a physical opponent, be it by words or blade, you remove a chain that could defeat you.
The Force shall free me. This essentially means just trust the Force. It will guide you, and you will use it.
There are a few more tenets that the Sith have that aren't officially part of the Qotsisajak.
The first is: Do not Love. Love leads to mercy, and mercy is a bad thing.
Be ambitious and imaginative, but also resourceful and cautious.
Be ruthless and cunning.
Serve yourself first and foremost.
Be passionate about everything, but do not let your emotions rule you.
Do not help others. Internal battles won by the self give the best rewards.
Conflict breeds strength. Pacifism breed stagnation.
The Sith were and are largely self-reliant. You can never expect one Sith to help another. If it does happen, there is always a cost. This was why there was so much infighting in every Sith Order ever. Darth Revan and Darth Malak's Sith Empire was at war with itself. Darth Bane's Rule of Two was war between Master and Apprentice. Darth Krayt's Rule of One was little more than the Jen'ari Sith, though by that point, the Sith species was largely considered a myth, even by Darth Bane.
Now, you may ask: how does this apply to day-to-day life for those that are incapable of using the Force?
It's quite simple, actually. The tenets all revolve around the idea of evolving and overcoming adversity. You fight, learn your flaws, fix them, and fight again, before repeating the process again. While actively seeding discord isn't required, it is encouraged. And just like power has multiple meanings, so does conflict.
In this case, conflict can refer to even a simple game of Go or Chess. It can be the struggle of a student falling behind in class, or the stress of a CEO trying to save a sinking business. Any turmoil is an experience to learn from. To not learn is a fallacy.
As I have said to many others, it is the duty of fools to learn, and we are all fools in this universe.
Laisvas here once more.
I would ask you to review with any questions about the Sith or the Dark Side you would like to see me speak of.
May the Force be with you.