Śāstra — Sciences & Arts
शास्त्र — विज्ञान एवं कला
Every technical treatise. Promoted to a top-level division deliberately: the Vedāṅgas and Upavedas are a real traditional grouping, and a reader looking for Āyurveda should not have to traverse three levels of scripture classification to reach Caraka.
The six limbs: Śikṣā (phonetics), Vyākaraṇa (grammar), Chandas (metre), Nirukta (etymology), Jyotiṣa (astronomy and astrology), Kalpa (ritual procedure).
Āyurveda, Dhanurveda, Gāndharvaveda and Sthāpatyaveda — medicine, warfare, the performing arts and architecture.
The specialised treatises that are neither Vedāṅga nor Upaveda: mathematics, poetics, Kāmaśāstra, and the nibandha digests.