The 12121 check digit algorithm

[Loyde W Hales]

In article <599 at xdos.UUCP> doug at xdos.UUCP (Doug Merritt) writes:
>In article <1498 at skye.ed.ac.uk> ken at aiai.UUCP (Ken Johnson) writes:
>> * The 12121 check digit algorithm. This version Ken Johnson, AIAI,
>> * Edinburgh University, 1989. You may freely use, modify or copy
>> * this code, declaim it in public houses or paint it on walls.
>> * But if you sell it at a profit, I want a share please.
>
>If you seriously want the legal right to control commercial usage,
>you must follow the international copyright law in such matters.
>Since you gave no copyright notice (which is required to say "copyright"
>along with your name & year of publication), this is now public domain.

Technically, this is true.  No one should release something the rights of
which they want to keep without the ``copyright'' mark.  You should also
include your name.

Despite that, there is some legal protection offered in the above statement.
Not being a lawyer, I can't give you exact details.  BUT, if you can convince
a court that the statement has AUTHOR, DATE, and a STATMENT OF PROTECTION,
you may be able to hold your rights.  If you want to have the protection,
though, you do need to act.  Once your claim is publically challenged, you
have to take action to protect it, as I understand the law.

One other thing to note:  if you do plan to keep a copyright, you are well
advised to file a copyright form with your country's ``copyright'' office.
If you don't want to spend the filing fee, at least take measures to
demonstrate the date, like mailing a copy to yourself (certified) or having
everyone in your office sign a statement of date/release.

Reason: while you have a copyright just by writing ``(C) 1990 by Johnson,''
it may not be enforcable if you cannot demonstrate the date.  I know all
about the international agreement for patents/copyrights, but US law does
limit rights under many odd circumstances.  The safest way to protect
yourself is the copyright office.

Afterall, if I claim I wrote this code in 1986...

According to the US Office of Copyrights and Patents, you should minimally
print the following information on any copyrighted material, preferably as
close to quoting this as possible:

	Copyright 1990 by Ken Johnson
	All Rights Reserved by Author

Hope this is helpful to someone....



-=-

                                Department of Computer and Information Science
Loyde W. Hales, II                      The Ohio State University
lwh at cis.ohio-state.edu          2036 Neil Avenue Mall, Columbus, Ohio  43201