What is the legal ruling for standing up to perform the Sunnah prayers immediately after completing the Fard prayer?

Supplications and Remembrances After Prayer (الأذكار بعد الصلاة)

• It is Wajib (necessary).
• It is Sunnah (Prophetic practice).
• It is only permissible (Mubah).
• It is legally disliked (Makruh).