ORA-65096: invalid common user or role name

sys@LUOCS12C> create user luocs identified by oracle default tablespace luocs;create user luocs identified by oracle default tablespace luocs            *ERROR at line 1:ORA-65096: invalid common user or role namesys@LUOCS12C> !oerr ora 6509665096, 00000, "invalid common user or role name"// *Cause:  An attempt was made to create a common user or role with a name//          that wass not valid for common users or roles.  In addition to //          the usual rules for user and role names, common user and role //          names must start with C## or c## and consist only of ASCII //          characters.// *Action: Specify a valid common user or role name.//根据错误提示了解，在CDB中用户得以C##开头，如下：sys@LUOCS12C> create user c##luocs identified by oracle default tablespace luocs;User created.