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

Results for*.fullnet.net

Logged At	Not Before	Not After	Common Name	Matching Identities	Issuer Name
2019-12-11T22:10:43.744	2019-12-11T21:10:43	2020-03-10T21:10:43	*.fullnet.net	*.fullnet.net	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-12-11T22:10:43.744	2019-12-11T21:10:43	2020-03-10T21:10:43	*.fullnet.net	*.fullnet.net	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-12-11T22:10:43.587	2019-12-11T21:10:43	2020-03-10T21:10:43	*.fullnet.net	*.fullnet.net	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-12-11T22:10:43.587	2019-12-11T21:10:43	2020-03-10T21:10:43	*.fullnet.net	*.fullnet.net	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-09-12T19:50:25.754	2019-09-12T18:50:24	2019-12-11T18:50:24	*.fullnet.net	*.fullnet.net	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-09-12T19:50:25.754	2019-09-12T18:50:24	2019-12-11T18:50:24	*.fullnet.net	*.fullnet.net	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-09-12T19:50:24.887	2019-09-12T18:50:24	2019-12-11T18:50:24	*.fullnet.net	*.fullnet.net	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3
2019-09-12T19:50:24.887	2019-09-12T18:50:24	2019-12-11T18:50:24	*.fullnet.net	*.fullnet.net	C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3