Class C refers to the local dangerous houses in the Appraisal Standard for Dangerous Houses, which means that the bearing capacity of some load-bearing structures can not meet the requirements of normal use, and some places are in danger, which constitutes a local dangerous house. It has nothing to do with real estate license. The following five categories are unable to apply for real estate license, projects developed by using collective land (such as houses with small property rights), houses built without approval (five certificates are incomplete), houses with unsecured land or houses, houses with arrears in housing transaction taxes, and houses with land or houses sealed up.