I suggest that the root of problem is that reference is itself not a verb, or wasn’t until it became one by corruption. Of course, people use it as a verb all the time, and assume it should be so employed, as several of the above examples and answers illustrate. I reckon “verbification” of nouns is the source of many contemporary language conundrums.

What adding to confusion is the now-common dual meanings of reference, in which we make reference to a reference. Something nitpicking might argue that shouldn’t read, “make reference to a referent” but no one says that except linguists talking about language technicalities (or in other similar specialized usage).

I suspect that “referenceable” as a corruption of “referable” has come to be common especially because of frequent and increasing use in information technology (per the somewhat convoluted argument above) and in increasingly technological society, where more and more information necessitates more and more references. Its just a word that gets used more often, so corruption becomes more virulent and rampant. What is good about a reference when it isn’t referable?

Besides the technology context (where, more or less, “refer(ence)able” describes a characteristic of a data element), I most often hear it used when people are talking about disclosure and some work or information can be shared. I think there is a subtle difference in meanings in this usage between whether something can be shared (a) by dint of its own capacity, or (b) because rules permit it. If anything, is needed, what would it be? I agree in all of the above cases with the term “referable”, but I believe it is more correct. “Referenceable” is common and most likely

prevalent.