Which of the people with job title code Sales Person are not Clerical Staff?
SELECT T1.staff_name , T1.staff_gender FROM staff AS T1 JOIN Staff_Department_Assignments AS T2 ON T1.staff_id  =  T2.staff_id WHERE T2.job_title_code  =  "Sales Person" EXCEPT SELECT T1.staff_name , T1.staff_gender FROM staff AS T1 JOIN Staff_Department_Assignments AS T2 ON T1.staff_id  =  T2.staff_id WHERE T2.job_title_code  =  "Clerical Staff"
job title code 'Sales Person' and not 'Clerical Staff' refers to selecting individuals with the job title code 'Sales Person' and excluding those with the job title code 'Clerical Staff';