What kind of a Bitcoin Address is this?

[100bitcoin]

https://blockchair.com/bitcoin/address/d-cf58a3f9625389423be30888d259c0fd

[BrewMaster]

what you are looking at is an OP_RETURN output script and as far as i know there is no address format or encoding defined for these types of script in bitcoin.
however with a closer look this output is a special OP_RETURN that is used in OMNI layer, i am not familiar with the encodings in that layer but it is possible that this special encoding is used to indicate and OMNI transaction.

[darosior]

What BrewMaster said, and this is a tether transaction : https://omniexplorer.info/search/2be8d89a0cee8da25d240013cceadd7aabca8d25950cfe0e56048ef0404db63c

EDIT: There are some funny omni tokens involving that address https://omniexplorer.info/address/35hK24tcLEWcgNA4JxpvbkNkoAcDGqQPsP 

[seoincorporation]

what you are looking at is an OP_RETURN output script and as far as i know there is no address format or encoding defined for these types of script in bitcoin.
however with a closer look this output is a special OP_RETURN that is used in OMNI layer, i am not familiar with the encodings in that layer but it is possible that this special encoding is used to indicate and OMNI transaction.

This is right if you take a look to the same transaction but in another explorer, you will see the OP_RETURN output:

https://www.blockchain.com/btc/tx/0f8012f195918d16c44d8cf77dc8c00f9abc6ed7e3be5fea3955ce379ec24e3d

This is not a valid addy to send or receive.

[BrewMaster]

This is not a valid addy to send or receive.

well, technically only scripts are valid and everything else is just our agreement. with that said an address is just a contract that majority of bitcoin wallets and tools such as explorers have agreed upon. so for example when you see a base58 encoded string that starts with a 0 byte and has a length of 20 bytes + 4 byte checksum, you translate it into a P2PKH script.
i think this is just an attempt by blockchair to make OP_RETURN scripts more human readable like other scripts that have addresses. although i couldn't find any documentation about it.