With the war in Ukraine having entered its six month, and with the taking and retaking of territories within Ukraine, there has been a need by nonmilitary personnel to get out of said areas quickly, as the need arises, sometimes at a moment's notice. That being said, such evacuations mean that there is little time for preparation and items must be left behind and along those lines the NBU has instructed the banks in the warzones to deface/deliberately damage all banknotes in the event of an evacuation. The statement from the NBU reads as such, "Taking into account the conduct of military (combat) actions or their possible threat, in accordance with the requirements of the regulations of the National Bank, in case of impossibility to take out cash, banks must damage it in order to bring the banknotes into non-payment condition.", in addition to being ordered to deface/damage the banknotes the NBU has also given instructions as to the methods for the defacing/destruction of the notes, "Banknotes can be damaged mechanically (cutting off at least half of the banknote and destroying it; cutting it in half or into three parts; drilling three or more holes in the banknote) or by using special solutions or other coloring substances with coloring of at least 50% of the total area of the banknote.".  See the press release from the NBU here. https://bank.gov.ua/ua/news/all/pid-chas-rozrahunkiv-gromadyanam-krasche-vidmovlyatisya-vid-banknot-z-otvorami-ta-inshimi-poshkodjennyami 

It is also illegal to spend such banknotes once they have been defaced/deliberately damaged, and that seems to be an issue in areas near the war zones. As occupying forces move in they, or others of an unscrupulous nature (looters), will confiscate the defaced/damaged notes and ether intentionally put them back into circulation in hopes of destabilizing the local economies or spend them as if they were their own.  The 500 Hryven banknotes in the image above, taken from the NBU press release, are of the old design last used in 2015 (3rd generation Hryvnia) meaning that both old and new notes (4th generation) could be, were, defaced/intentionally damaged. It is unknown at this point if the NBU has serial number ranges for new notes that were defaced/intentionally damaged at occupied/abandoned banks, but I assume that information is available to them, nor is it known if there are records for older notes pulled from circulation that were defaced/intentionally damaged, but it's doubtful. 

Please, if you see such notes online, specifically for sale, report them and the sellers as these notes are illegal to own at this time and directly impact innocent people. Furthermore, any jamoke or jabroni can pop three or four holes into a banknote, or deface it in any manner described above, and claim that it is the real article. Stay away from these folks!