You are right! There are no specific rules for naming group 18 ions because group 18 elements (noble gases) are very unreactive and rarely form ions.

Here's why:

* Stable electron configuration: Group 18 elements have a full outer shell of electrons, making them incredibly stable. They don't readily gain or lose electrons to form ions.

* High ionization energy: It takes a lot of energy to remove an electron from a noble gas atom, making ion formation extremely difficult.

* Low electron affinity: Noble gases have little tendency to gain electrons.

While it is theoretically possible to form ions of noble gases under extreme conditions (e.g., in plasmas), these are not commonly encountered in everyday chemistry.

Therefore, there's no practical need to establish naming conventions for ions that are rarely observed.