lt (Otherwise):
"str"    (string) According to BIP22

Examples:
> bitcoin-cli submitblock "mydata"
> curl --user myusername --data-binary '{"jsonrpc": "2.0", "id": "curltest", "method": "submitblock", "params": ["mydata"]}' -H 'content-type: application/json' http://127.0.0.1:8332/


