> You don't even need a copyright notice. Under current US law (and that of many other countries that have harmonized their copyright regimes), copyright is automatic, and requires no notice at all. Obviously it is better/safer for you to put a copyright notice on everything you create, but it is not required. You will hold copyright on a work you create and distribute today, even if you don't put your name or the magic "Copyright 2024 $NAME" bit anywhere on it.

> I think there's some confusion here about copyright vs. licensing: those two things are independent, except of course that you need to hold the copyright to be able to set licensing terms. The default, without any provided license, is the most restrictive of one: that no one else has any rights toward the covered work.

There is no such confusion on my part, rather it's simply that I should've said "copyright and license notices" instead of just "copyright notice", but my entire point in that line is that the notice and the license are two different things. The only case where you'd put the entire license inline into the source code files is when the license notice is the entire license, for short licenses like 3BSD or MIT.

> Registering does, yes. In the US, at least, you cannot file suit to protect your copyright unless it is registered. I don't believe the presence or absence of a copyright notice matters one bit; ultimately regardless of the presence or absence of a copyright notice, if it ends up in court, everyone will be providing more documentation as to the provenance of the work in question.

> The dates you list in the copyright notice are perhaps useful for readers, but if a dispute ends up in court, part of the proceedings may involve determining the creation date/year of any bits under dispute, independent of what you put in the copyright notice. But in practice, with software, considering the stupid-long time things remain under copyright these days, the exact date doesn't matter much, as pretty much anything anyone is going to bring a dispute about is going to still be under copyright.

As to whether including a copyright notice on each file is useful, I will defer to the U.S. Copyright Office, which lists a few points in which a copyright notice is still useful.

https://www.copyright.gov/circs/circ03.pdf

> "Beyond a reasonable doubt" is a standard applied to criminal cases; civil cases have a lower burden of proof. But yes, you're always better off with things documented than not. A judge/jury will certainly appreciate a plaintiff or defendant who has all their ducks in a row vs. one that is disorganized. But they'll also be cognizant of (and try to determine) what the copyright holder intended to do, even if the documentation doesn't spell it out as clearly as one would like.

I'll quote from the document I linked above:

"In the case of a published work, a notice may prevent a defendant in a copyright infringement action from attempting to limit his or her liability for damages or injunctive relief based on an innocent infringement defense."

So yes, it definitely does matter. This is especially true if there's a possibility your source code could wind up being distributed in some fashion that you did not originally intend, e.g. outside of source control, possibly copied into a bigger repository, where it's easier to miss the separate NOTICE/LICENSE/etc.

> The law is not a computer; you're not likely to get away with copyright infringement just because the copyright holder missed some detail.

Yes, I know, color of your bits, whatever. (The notice I really need is a 8 paragraph long disclaimer I can affix to my posts to cover all of the things I already understand and don't need described to me again in a mildly condescending fashion.)

However, I will note that being legally boned due to a technicality is absolutely a thing that exists. Hell, this was the reality prior to the Berne Convention: even if you intended for something to have copyright protection, failing to put a copyright notice on it could indeed cause you to lose out on copyright protection. So I'm not sure what this has to do with anything here. Technicalities exist just as much in law and bureaucracy as they do in computers...

> No they don't. A "copyright notice"[0] is simply something that says "Copyright $YEAR $NAME". A "copyright license" is a list of terms that give people more rights to use and distribute the work than they would get under copyright law.

> You don't need to put licensing information in each source file. If everything in a project is released under the same license, noting the license in a single place is fine. If different files have different licenses, of course you'll need to note things specifically; though, again, if you don't want to put licensing information in each file, you can still note in a single place which files are under which license.

> But as I mentioned above, more documentation is better/safer than less. Personally I put licensing information in every source file of the things I release, even if every file is under the same license as the project as a whole.

I re-iterate again that I should have said "copyright and license notices". I really wish I had done that, because it could've saved a lot of typing to have gotten that part right.