It can be anything! An apex, subdomain, or even a URL.

Results for*.bitcoinwiki.us

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2019-05-29T13:34:35.365	2019-05-29T12:34:34	2019-08-27T12:34:34	bitcoinwiki.us	*.bitcoinwiki.us	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-05-29T13:34:35.365	2019-05-29T12:34:34	2019-08-27T12:34:34	bitcoinwiki.us	*.bitcoinwiki.us	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-05-29T13:34:34.306	2019-05-29T12:34:34	2019-08-27T12:34:34	bitcoinwiki.us	*.bitcoinwiki.us	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-05-29T13:34:34.306	2019-05-29T12:34:34	2019-08-27T12:34:34	bitcoinwiki.us	*.bitcoinwiki.us	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-03-10T12:32:20.26	2019-03-10T11:32:19	2019-06-08T11:32:19	oljh.de	*.bitcoinwiki.us	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-03-10T12:32:20.26	2019-03-10T11:32:19	2019-06-08T11:32:19	oljh.de	*.bitcoinwiki.us	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-03-10T12:32:19.336	2019-03-10T11:32:19	2019-06-08T11:32:19	oljh.de	*.bitcoinwiki.us	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-03-10T12:32:19.336	2019-03-10T11:32:19	2019-06-08T11:32:19	oljh.de	*.bitcoinwiki.us	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3