st: how to cite others' code?

[Rebecca Pope <rebecca.a.pope@gmail.com>]

Hello Statalist-ers,
Is there a standard format or set of guidelines for citing code
written by others? I am _not_ asking whether one ought to cite pieces
of code written by others, but what is required to be in that
citation. If a standard does exist, does it differ depending on
whether the code comes from Stata Corp, user-written ado files, or was
posted as an example to the list? I did try to search for this before
posting, but all I found were some posts relating to people not citing
others' code. If guidelines are already codified & available, I'm
afraid they have been obscured in my search results by this previous
discussion.

As a concrete example, Svend Juul posted a question a few days ago
about generating new variables in a command when a -varlist- is also
required. I do something similar in one of my programs, but Nick's
response (http://www.stata.com/statalist/archive/2011-02/msg00861.html)
is far more flexible than my solution to the problem. If I were to
replace my code with what Nick posted, how would that be correctly
cited?

Regards,
Rebecca
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