PETA (Indonesian: Pembela Tanah Air – Defenders of the Homeland) or Kyōdo Bōei Giyūgun (郷土防衛義勇軍) was an Indonesian volunteer army established on 3 October 1943 in Indonesia by the occupying Japanese. The Japanese intended PETA to assist their forces in opposing a possible invasion by the Allies. The word PETA itself means map in local language. By the end of the war, there were a total of 69 battalions (daidan) in Java (around 37,000 men) and Sumatra (approximately 20,000 men). On 17 August 1945, the day after the Indonesian Declaration of Independence, the Japanese ordered the PETA daidan to surrender and hand over their weapons, which most of them did. The Indonesian Republic's newly declared President, Sukarno, supported the dissolution rather than turn the organisation into a national army as he feared allegations of collaboration had he allowed a Japanese-created militia to continue in existence. https://en.wikipedia.org/wiki/Pembela_Tanah_Air
It's worth being aware of these guys, as their swords keep turning up on the collectors market. They are often called "Island Swords" or even "Last Ditch" but are in fact local made copies of, or are influenced by Japanese Shin-Gunto. Follow the link for more about them
I think these blades are collectable, but worth bearing in mind that they are not Japanese, and this effects resale value.