If you write die of disease like before with a specific disease's name, but without a specific time, if it takes more than 24 days for the human to die the 23 day rule will not take effect and the human will die at an adequate time depending on the disease.
When rewriting the cause and/or details of death it must be done within 6 minutes and 40 seconds. You cannot change the victim's time of death, however soon it may be.
Rules XXVIII

How to Use: XXIX
You cannot kill humans at the age of 124 or over with the Death Note.
You cannot kill humans with less than 12 minutes of life left in human calculations.
Rules XXIX

How to Use: XXX
If you have traded the eye power of a god of death, you will see a person's primary life span in the human world.
The names you will see with the eye power of a god of death are the names needed to kill that person. You will be able to see the names even if that person isn't registered in the family registration.
Rules XXX

How to Use: XXXI
The number of pages of the Death Note will never run out.
Rules XXXI

How to Use: XXXII
If someone possesses more than one Death Note, by visualizing the victim, then writing down the name in one of the Death Notes and the cause of death in the other, it will take effect. The order however, is unimportant, if you write down the cause of death in one Death Note and afterwards, write the name in the other, it will take effect.
This can also be accomplished by two Death Note owners working together. In this case, it's necessary that the two touch each other's Death Notes.
Rules XXXII

How to Use: XXXIII
If a person loses possession of a Death Note, they will not recognize the gods of death by sight or voice any more. If however, the owner lets someone else touch his Death Note, from that time on, that person will recognize the god of death.
In accordance with the above, the human who touched the Death Note and began to recognize the gods of death's image and voice, will continue to recognize it until that human actually owns the Death Note and subsequently loses possession of it.
Rules XXXIII

How to Use: XXXIV
The owner of the Death Note cannot be killed by a god of death who is living in the world of the gods of death.
Also, a god of death who comes to the human world, in the objective to kill the owner of the Death Note, will not be able to do so.
Only a god of death that has passed on their Death Note to a human is able to kill the owner of the Death Note.
Rules XXXIV

How to Use: XXXV
If a Death Note owner accidentally misspells a name four times, that person will be free from being killed by the Death Note. However, if they intentionally misspell the name four times, the Death Note owner will die.
The person whose name was misspelled four times on purpose will not be free of death by a Death Note.
Rules XXXV

How to Use: XXXVI
There are male and female gods of death, but it is neither permitted, nor possible for them to have sexual relations with humans. The gods of death also cannot have sex with each other.
Rules XXXVI

How to Use: XXXVII
When regaining ownership of the Death Note, the memories associated with the Death Note will also return. In cases where you were involved with other Death Notes as a well, memories of all the Death Notes involved will return.
Even without obtaining ownership, memories will return just by touching the Death Note. The whole Death Note it can not be a piece or a page.
Rules XXXVII

How to Use: XXXVIII
You will lose memory of the Death Note when losing its ownership. But you can regain this memory by either obtaining the ownership once again or by touching the Death Note. This can be done up to 6 times per Death Note.
If the 6 times are exceeded, the person's memory of the Death Note will not return and they will have to use it without any previous memory of it.
Rules XXXVIII

How to Use: XXXIX
Humans that have traded for the eye power of a god of death cannot see the name or life span of humans who have already passed away by looking at their photos.
Rules XXXIX

How to Use: XL
Whenever a god of death who had been in the human world dies the Death Note is left behind and is picked up by a human, that person becomes the owner.
However, in this case, only human that can recognize the god of death and its voice is able to see and touch the Death Note.
It is very unlikely, but if by any chance a god of death picks up the Death Note, that god of death becomes the owner.
Rules XL

How to Use: XLI
It is useless trying to erase names written in the Death Note with erasers or white-out.
Rules XLI

How to Use: XLII
The use of the Death Note in the human world sometimes affects other humans' lives or shortens their original life span, even though their names are not actually written in the Death Note itself. In these cases, no matter the cause, the god of death sees only the original lifespan and not the shortened lifespan.
Rules XLII i
Rules XLII ii

How to Use: XLIII
If a Death Note is owned in the human world against the god of death's will, that god of death is permitted to stay in the human world in order to retrieve it.
In that case, if there are other Death Note in the human world, the gods of death are not allowed to reveal to humans that Death Note owner or its location.
Rules XLIII i
Rules XLIII ii

How to Use: XLIV
If the Death Note that the god of death owns is taken away by being cheated by other gods of death and so forth, it can only be retrieved from the god of death who possesses it at the time. If there is no god of death, but a human possessing it, the only way that the god of death can retrieve it will be to first touch the Death Note and become the god of death that haunts that human. Then wait until that human dies to take it away before any other human touches it, or whenever the human shows a will to let go of it.
Rules XLIV

How to Use: XLV
As long as the god of death has at least once seen a human and knows his/her name and life-span, the god of death is capable of finding that human from a hole in the world of the gods of death.
Rules XLV

How to Use: XLVI
There are laws in the world of gods of death. If a god of death should break the law, there are 9 levels of severity starting at Level 8 and going up to Level 1 plus the Extreme Level. For severity levels above 3 the god of death will be killed after being punished.
For example, killing a human without using the Death Note is considered as the Extreme Level.
Rules XLVI

How to Use: XLVII
Losing memory of the Death Note by passing on the ownership to another, or by abandoning its ownership will only occur when someone is actually killed using that Death Note. You will not lose memory of the Death Note, for example, if you merely owned it and had not written anyone's name. In this case, you will not be able to hear the voice or see the figure of the god of death any more. You will also lose the eye power of the god of death you traded with.
Rules XLVII

How to Use: XLVIII
The god of death will not die from lack of sleep. Moreover, gods of death do not really need sleep. The meaning of sleep for gods of death is essentially different from humans and is merely laziness.
Especially gods of death living in the human world that have passed on their Death Note shouldn't be lazy, as they are required to see the death of the human, but it is not that they are not allowed to sleep.
Rules XLVIII

How to Use: XLIX
Only 6 Death Notes are allowed to exist at a time in the human world. Of course, the Death Note that the god of death owns does not count. This means only 6 gods of death that have passed on their Death Note to humans can stay in the human world.
Rules XLIX

How to Use: L
One god of death is allowed to pass on Death Notes to only 3 humans at a time.
It is possible for a single god of death to hand out up to 6 Death Notes, for example, by handing 3 humans 2 Death Notes each.
In other words, one human could own all 6 Death Notes.
Rules L

How to Use: LI
However, if a seventh Death Note is owned by a human in the human world, nothing will happen even if used.
LI

How to Use: LII
In the event that there are more than 6 Death Notes in the human world, only the first 6 Death Notes that have been delivered to humans will have effect.
The seventh Death Note will not become active until one of the other 6 Death Notes are burned up, or a god of death takes one of them back to the world of the gods of death.
Rules LII

How to Use: LIII
The Death Note will not take effect if you write a specific victims name using several different pages.
But the front and back of a page is considered as one page. For example, the Death Note will still take effect if you write the victim's surname on the front page and given name on the back.
Rules LIII

How to Use: LIV
In order to make the Death Note take effect, the victim's name must be written on the same page, but the cause of death and situation around the death can be described in other pages of Death Note. This will work as long as the person that writes in the Death Note keeps the specific victims name in mind when writing the cause and situation of death.
Rules LIV

How to Use: LV
In occasions where the cause and situation of death is written before the victim's name, multiple names can be written as long as they are written within 40 seconds and the causes and situations of death are not impossible to occur.
In the occasion where the cause of death is possible but the situation is not, only the cause of death will take effect for that victim. If both the cause and the situation are impossible, that victim will die of heart attack.
Rules LV

How to Use: LVI
When you write multiple names in the Death Note and then write down even one cause of death within 40 human seconds from writing the first victims name, the cause will take effect for all the written names.
Also, after writing the cause of death, even if the situation of death is written within 6 minutes and 40 seconds in the human world, the situation will only occur to the victims whom it is possible. For those where the situation is not possible, only the cause of death will occur.
Rules LVI

How to Use: LVII
In the Death Note, you cannot set the death date longer than the victim's original life span. Even if the victim's death is set in the Death Note beyond his/her original life span, the victim will die before the set time.

How to Use: LVIII
By manipulating the death of a human that has influence over another human's life, that human's original life span can sometimes be lengthened.
If a god of death intentionally does the above manipulation to effectively lengthen a human's life span, the god of death will die, but even if a human does the same, the human will not die.
Rules LVIII

How to Use: LIX
A human death caused by Death Note will indirectly lengthen some other human's original life even without a specific intention to lengthen a particular person's original life span in the human world.
Rules LIX

How to Use: LX
After a god of death has brought the Death Note to the human world and given its ownership to a human, that god of death has the right to kill the human using his/her own Death Note for reasons such as disliking the owner.
Rules LX

How to Use: LXI
Even if a new victim's name, cause of death, or situation of death is written on top of the originally written name, cause of death or situation of death, there will be no effect on the original victim's death. The same thing will also apply to erasing what was written with a pencil, or whitening out what was written with a pen, in attempt to rewrite it.
Rules LXI

How to Use: LXII
Once the victim's name, cause of death and situation of death have been written down in the Death Note, this death will still take place even if that Death Note or the part of the note in which it has been written is destroyed, for example, burned into ashes, before the stated time of death.
If the victim's name has been written and then the Death Note is destroyed in the middle of writing the cause of death, the victim will be killed by heart attack in 40 seconds after writing the name.
If the victim's name and cause of death have been written and the middle of writing the situation of death, then the victim will be killed within 6 minutes and 40 seconds via the stated cause of death if the cause is possible within that period of time, but otherwise, the victim will die by heart attack.
Rules LXII

How to Use: LXIII
No matter what medical or scientific method may be employed, it is impossible for humans to distinguish whether or not the human has the eye of power of a god of death. Even gods of death cannot distinguish this fact, except for the very god of death that traded his/her eye power with that human.
Rules LXIII

How to Use: LXIV
The following situations are the cases where a god of death that has brought the Death Note into the human world is allowed to return to the world of gods of death:
When the god of death has seen the end of the first owner of the Death Note brought into the human world and has written that human's name on his/her own Death Note.
When the Death Note which has been brought in is destroyed, like burned, and cannot be used by humans anymore.
If nobody claims the ownership of the Death Note, and it is unnecessary to haunt anyone.
If, for any reason, the god of death possessing the Death Note has been replaced by another god of death.
When the god of death loses track of the Death Note which he/she possesses, cannot identify which human is owning the Death Note, or cannot locate where the owner is, and therefore needs to find such information through the hole in the world of gods of death.
Even in the situations 2, 3, and 4 above, gods of death are obliged to confirm the death of the first owner and write down that humans name in his/her Death Note even when he/she is in the world of gods of death.
Rules LXIV

How to Use: LXV
In the world of gods of death there are a few copies of what humans may call user guidebook for using the Death Note in the human world. However, the guidebook is not allowed to be delivered to humans.
It is perfectly okay for gods of death to read the guidebook for him/herself and teach humans about its contents, no matter what the content may include
Rules LXV

How to Use: LXVI
Some limited number of Death Notes have white or red front covers, but they would make no difference in their effects, as compared with the black cover Death Notes.