International ongoing systematic studies (IOSS) on intermediate & advanced level by well known advanced and senior teachers. 

Ongoing systematic studies on intermediate level (Iyengar System Level 2) and on advanced level (Iyengar System Level 3) cover the practise of asanas, pranayama, philosophy, dharana, and dhyana.

LOY offers 3 different systematic ways for ongoing studies and extra qualifications. 

Art: Asanas, Pranayama in combination with philosophy
Science: Healths aspects, remedial/therapeutic work, studies 
Comparative Philosophy: e.g. Eastern, Western philosophy referring to yoga and its subjects