stamped hasgacha

we’ve always used things that said “kosher for Passover”
this site (psak of rav abadi?) seems to say that it is sufficient to look at the ingredients.
why is this ?
why is this opinion different from all other opinions?
thanks
Pinhas

Good question. One asked here frequently. You can search the posts for some exciting discussions.
Here’s a short one I found. Determining kashrus based on ingredients

It’s different from some opinions, and aligns closely with others. :man_shrugging: