The praenomen "Appius" was "used only by the gens Claudia." False.
While "Appius" was perhaps the most restricted of the commonly seen praenomina (primarily during the period of the Republic), it could nevertheless be found in the following gentes in addition to the Claudii: the Annii, Modii, Popidii, and Iunii/Junii. (Reference: Charles Davis Chase, "The Origin of Roman Praenomina.")
Wiktionary perpetuates this error, in its article titled "List of Roman Praenomina".
But no doubt they will soon lift what I have written here, in order to correct their own article on Roman praenomina.
Just as Wikipaedia plagiarized my article "Roman Naming Practices During the Principate Period" in their article titled "Praenomen".
In their article on the praenomen, the folks at Wikipaedia clearly lifted their information on the number and frequency of praenomina from my article. They write: "Compared to most cultures, Romans used very few given names: the common praenomina were fewer than 40. The 17 most common male praenomina accounted for 98% of all male Roman names[1]. The most popular - Lucius, Gaius, and Marcus - constituted 59% of the total."
The reference they give for this is the Corpus Inscriptionum Latinarum, which shows that they don't know what they are talking about, because the CIL does not provide conveniently worked-out percentages of praenomina usage.
I had worked out those percentages myself, based on a compilation of praenomina made by Charles Davis Chase (whom I credited in my own article), and this compilation of Chase's was taken only from the first volume of the CIL.
Wikipaedia is frequently wrong and frequently plagiarizes other sources without giving sufficient credit to those sources. I know that our own Primus Pilus on this site has had this same experience with Wikipaedia.
I think that anyone here who wants to be taken seriously should refrain from quoting Wikipaedia as a source to back up their debates, arguments, whatever on any particular subject. While I, myself, admit to having been guilty on occasion of referring to a Wikipaedia article for a quickie definition, I try not to make a habit of it. Because that is just plain lazy.
In fact, henceforth I am boycotting Wikipaedia. And anyone here who quotes from a Wikipaedia article is going to be the most deserved object of my mockery and derision.
-- Nephele