No Dolphin52 you have not provided any such numerous authoritative sources for the definition I understand why you feel that my request for documentation doesn t make sense to you The request needs to be understood in the context of A Wikipedia policies and guidelines and B rules of legal analysis What you have done is provide numerous quotations taken out of context from various court cases and from other sources Many of the court cases did not even involve federal taxes Further assuming you are still defending the verbiage that was removed from the article you appear to be arguing that an excise in the U S constitutional law sense is limited to a tax on privileges etc That argument is completely invalid There are two problems with the argument First none of the sources you provided say that all excises in the constitutional sense must always involve a tax on a privilege and none of the sources you provided stand for that proposition Second by contrast I have specific federal court cases where the courts ruled various events or activities to be taxable events yet those activities or events do not involve any privilege Later I ll repost on this talk page the actual text that was removed from the article and I will again summarize applying Wikipedia policies and guidelines and rules of legal analysis why the removed material was objectionable The analysis you provided violates various Wikipedia rules and it also violates some of the basic tenets of legal analysis Now for some more background The argument that an excise in the constitutional sense must always involve a privilege to be valid is called a tax protester argument It is not only legally invalid but it is worse it is also legally frivolous A person can be penalized monetarily for even raising such an argument on a federal tax return or in a federal court Later I ll also post examples of actual court cases where people specifically argued using the privilege argument that their income could not be taxed under the federal income tax laws and their arguments were ruled invalid On a separate note it should be obvious that the argument that a excise again in the constitutional sense not the statutory sense must always involve a privilege is legally nonsensical for an entirely separate reason Engaging in criminal activity is not a privilege in any correct legal sense Yet the United States Supreme Court has repeatedly ruled that the federal income tax which is an excise may validly tax the receipt of funds in a criminal activity specific examples funds received by extortion or embezzlement even though the wrongdoer is required to return the funds to their rightful owner And the federal courts have repeatedly and overwhelmingly ruled that the federal income tax is fundamentally an excise not a direct tax I know of only a couple of cases off the top of my head where a federal court actually ruled a particular federal income tax to be a direct tax and one of those cases was later overruled On this basis alone an excise can not possibly be limited to ONLY a tax on a privilege etc Stay tuned