This image is in the public domain because according to Article 4, case 2 of the Polish Copyright Law Act of February 4, 1994 (Dz. U. z 2006 r. Nr 90 poz. 631 with later changes) "governmental symbols, documents, materials and signs are not subject to copyrights". Hence it is assumed that this image has been released into public domain. However in some instances the use of this image in Poland might be regulated by other laws.
This file is licensed under the Creative CommonsAttribution ShareAlike 2.5 License. In short: you are free to share and make derivative works of the file under the conditions that you appropriately attribute it, and that you distribute it only under a license identical to this one. Official license