TABLE 2: Columns Field
Value of Field What It Means
NULL The columns field is not applicable to the permission being granted. The value will be NULL for any DELETE or INSERT permission records retrieved from the table.
0x01 (bit 0 set on) When bit 0 of the field is set on, the user has permission to SELECT or UPDATE (depending on the ACTION field) all of the columns in the table. This value is the default for all SELECT/UPDATE permissions, unless column-level security is specifically set.
Any value When you use column-level security, SQL Server >0x01 will set a bit on in the column's bit mask to identify which columns you have permission to SELECT or UPDATE.