Now, these are some interesting notes on Flask. Why does Flask have the weird license? It doesn’t quite seem to be exactly a BSD license. Here is the explanation.
20160810/http://flask.pocoo.org/docs/0.11/
20160810/http://flask.pocoo.org/docs/0.11/license/#flask-artwork-license
20160810/http://lucumr.pocoo.org/2010/6/19/licenses-dammed-licenses/