Code copying and reuse from Base

There is a function in Base called show_unquoted that I would like to copy and very slightly modify for use in a package I am building. Now, if I was writing a paper this would be blatant plagiarism so whats the deal in the realm of software? Is this possible with explicit permission? Never possible?

What should I person do in this circumstance?

See the license.


It is plagiarism only if you don’t acknowledge the source.