Very few things are taboo or against the Laws and Etiquette that govern the Worlds as a whole. But the most notable are:
1. Incest between a male or a neodrach in male form and a female or neodrach in female form. The reasoning behind this is, while there are forms of contraception within the Worlds, they are not guaranteed (not the semi-permanent ones, at least) and as such the chance of begetting a child off an incestuous coupling is too great to risk. Some races have cultural beliefs/practices that state if both parties are of the age of majority and willingly consent with sound minds to the relationship and all that that entails that the Law/taboo that bans that relationship is negated. But it is rarely practiced.
2. Forcing any individual into any sexual act. If express consent is not given, then it is rape. There are no distinct definitions that label severity or kinds of rape. If a sexual act, penetration or otherwise, is performed forcibly upon another Dhaoine, it is rape. The punishment across the Worlds for such an act is death.
3. Abuse/overall mistreatment of a child or individual incapable of defending themselves. Depending on the severity and length of time the abuse/mistreatment has occurred for depends on the punishment for the breaking of this Law.
4. Removing the wings of a winged Dhaoine without a proper trial or informing the Eighth Qishir of the transgression that such a punishment is in response to.
5. Forcing an individual — especially a Qishir — into any type of slavery with sexual slavery being the worst viewed of the types. This is taboo because prostitution and other related sex work is not illegal within the Worlds so long as the individuals engaging in said acts are willing participants.
While there are more, these are the most notable. The Laws state what is illegal and the responding Etiquette is the punishment/response due to whoever breaks the Law. There is only one instance where an Etiquette was penned first and its partner Law second. That is the Etiquette of Fair Punishment and the Law of Retribution for the Disciplined.
Most of the time when an Etiquette is carried out it is a Qishir who does it but not always. Any Dhaoine within the Worlds may stand up and defend the undefended and see that justice is done fairly.