Only hospital-based facilities should have two CCNs. In CROWNWeb always use the CCN associated with your hospital (xx00xx, xx01xx, xx02xx, xx13xx, xx33xx.) Admitedly, this is confusing because CROWNWeb calls your other CCN (xx23xx) your "Hospital CCN," but don't use that one.
CMS Certification Number (aka Medicare Provider Number)
CMS Certification Number. It is your facility's 6-digit Medicare provider number.