I found 18635073 wallets having this form x-ff8bb9190e0e969f5b8176dba0c0f161
where x can be s,d,m or another letter followed by - and a string of hex digits ...
they don't look like hash160 representation so what are they ?
It's Blockchair.com's way of showing OP_RETURN outputs. I'm not sure how "real" those are, and if you'd get the same result if you'd get the data from your own Bitcoin Core installation. For most purposes you can ignore them.where x can be s,d,m or another letter followed by - and a string of hex digits ...
they don't look like hash160 representation so what are they ?