[jgmatpdx]

The BSD license would like a word with you:

"Redistribution of source code must retain the above copyright notice ..."

Or how about the Apache license:

"You must retain, in the Source form of any Derivative Works that You distribute, all copyright, patent, trademark, and attribution notices from the Source form of the Work,"

Maybe the MIT license:

"The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software."

and so forth.

[daurnimator]

Coming from Lua, where everything is MIT:

"substantial license"

If you copied a couple of functions for a class the uni would have big problems if you provided no attribution; though the license does not require it.