The Eight Limbs of Yoga, or Asta-anga (ashtanga)-yoga

Yama | Niyama | Asana | Pranayama | Pratyahara | Dharana | Dhyana | Samadhi

Niyama:

(Sutra II.32) Principles of self-awareness, established observances:

Sauca: Cleanliness, Purity, from suc 'to be radiant'

Samtosa: Contentment,

Tapas: Spiritual zeal, fervor, burning desire - Iyengar (austerity - Feuerstein)

Svadhyaya: Study of the self; knowledge of self through the scriptures. "Checking oneself to see if the principles of yoga are being followed." - Iyengar

Ishvara Pranidhana: Concentration/Surrender/Devotion to the Divine. The divine is "the target of concentration." - Iyengar. Placing oneself in the rythm of the divine. Feeling onself a part of the order of things.

"Yama and Niyama are not only the foundation of yoga, but the reflection of our success or failure at its higher levels."
- BKS Iyengar

"Principles which run contrary to yama and niyama are to be countered with the knowledge of discrimination."
II.33 vitarkabadhane pratipaksabhavanam