I search for solutions in this order: Past Code, Unreal Source, Wiki, BUF, groups.yahoo, google, screaming at monitor. – RegularX

From Unreal Wiki, The Unreal Engine Documentation Site

This category contains images in the public domain.

Media in category "PD images"

The following 9 files are in this category, out of 9 total.

Copyleft.png 2,841 bytes	Delete.png 3,112 bytes	Example.jpg 61,136 bytes	M-en-pagetabs.png 7,587 bytes
M-en-recentchanges.p… 74,804 bytes	M-en-userlinks.png 10,177 bytes	PD-icon.png 2,157 bytes	Singly-linked-list.p… 2,349 bytes
Wikibus.png 4,390 bytes