ions - Naming ionic compounds with multiple cations and anions

I have seen complex ionic compounds that have mixed anions and/or mixed cations. For Example I have seen this:

$$\ce{NaKCl2}$$

Also known as Sodium Potassium Chloride. The only information I can find on this is an ion cotransporter for sodium potassium and chloride ions.

Anyway the structure of a single monomer of this would be $\ce{Na+}$ $\ce{Cl-}$ $\ce{K+}$ $\ce{Cl-}$

I have also thought of this as a possibility: $$\ce{Na3ClO}$$

This looks very similar to sodium hypochlorite in terms of its formula but has a different structure. The structure of it would be $\ce{Na+}$ $\ce{Cl-}$ $\ce{Na+}$ $\ce{O^2-}$ $\ce{Na+}$

I know that naming mixed ionic compounds is not easy unlike naming simple ionic compounds(which itself can be hard if you don't know the name of a particular polyatomic ion). But how would I go about naming these mixed ionic compounds?

Answer

I propose you consult the recommendations of the International Union of Applied Chemistry (IUPAC), in particular the Red Book as reference. Obviously, you deviated for a reason from the Hill formula of $\ce{NaKCl2}$ (that were $\ce{Cl2KNa}$) some data bases adhere to.

As already presented in rules IR 4.4.2.1, and IR 4.4.2.2, the order of the elements within the formula may be arranged either by their relative electronegativity (starting by the element of least electronegativity), or by alphanumeric order, respectively. So rules in section IR 5.4 subsequently discriminate between electropositive constituents to be named prior to electronegative ones in the "overall name". In addition (quote):

"The order of citation is alphabetical within each class of constituents (multiplicative prefixes being ignored), except that hydrogen is always cited last among electropositive constituents if actually classified as an electropositive constituent."

The same reference provides numerous examples of application useful to look at, too. Page 76 (of the book, not the pdf) is a good place to start. As in nomenclature of organic compounds, there are instances you want to point the attention not only to the stoichiometric composition of the compound, rather than to different constitutional isomers.