Hi! I'm very new in this hobby and just got this 5 peso banknote. I can't find any catalog or reference about this note. The person from whom it came just told me that it was a limited edition. It can be unofficial issue or a total fake. Here's the note.
Are these still in use because the page of the latest note, linked by rsirian1, state they are from ‘95-’97 and the other overprint notes are from the late 80s and early 90s. The overprint is from 2019 if it's official it might simply missing from the catalog (Krause's last catalog update has 2018 data at best).
Base on Wikipedia the banknote was demonetized in 2017 and printing stopped in 1995. It could be a third party stamp but the serial number is on top of the print.
Looks to be this banknote that has been stamped on the front. Probably done by a third party (but I could be wrong).
I agree with @rsirian. Looks to be P-180 by the signature & Seal Type 5 with a stamp overprint. My SCWPM states that ”Commemorative overprints not listed were produced privately in the Philippines" under the 1986-1991 Commemorative Issues title (p. 868 of my 24th Ed).
There about 5-6 variations (different prints) of the 5 Peso currency. I am out of the country right now but I will try to gather up all variations that I have and post it here when I return. Unfortunately, any currency dated 2009 and under are no longer accepted as a form of payment. 1994 and below for coins.
By the way, they did not just do this in the 5 Piso notes. They did this to notes up to 100 Piso (that I can tell). I have not seen those marks in 200, 500 and 1000 notes. I also haven't seen the marks on 2010 up to 2024 on any notes.