Unknown Address Format Parsing Bitcoin Addresses from Blockchair Data I've obtained a list of all current Bitcoin addresses with balances from Blockchair, which is downloadable from their data repository located here.  I have downloaded the Bitcoin / Addresses TSV database dump.
The list consists of:

~23m P2PKH (1xxx) addresses
~5.8m P2SH (3xxx) addresses
~1.3m Bech32 (bc1xxx) addresses

However, there are also ~400k addresses that have prefixes that I don't recognise, including:

d-xxx (example: d-b697921d996831d1a26ca8d8e92571c1)
m-xxx (example: m-942943e227462513f33c4f32ec6f1e56)
s-xxx (example: s-2ad548f2459c0ed6123400e5d61a479e)

Are these valid Bitcoin addresses?
If they are, how do I view information about them?
If they are not, any idea why they appear in the dump of current Bitcoin addresses from Blockchair?
Having investigated this following @MCCCS answer, the following is information about the addresses provided by Blockhair support:

In fact, there are no addresses on the Bitcoin blockchain. There are
only scripts, some of them are standard and can be converted to a
Bitcoin address, some of them can’t — like nulldata (OP_RETURN)
outputs, nonstandard, and bare multisig. We use the d- prefix for
nulldata, m- for bare multisig, and s- for everything else.
This is briefly mentioned in this API documentation section:
https://blockchair.com/api/docs#link_300

Therefore, these addresses (for want of a better word) are valid transactions on the Bitcoin blockchain.
The prefixes used are:

d- nulldata
m- bare multisig
s- everything else

In conclusion, the data is valid but the outputs are not addresses in the normal sense of the word.
A link to the issue I raised on the Blockchair GitHub is here.