Itihasa-Purana declared the fifth Veda
'Itihasa-purāṇaṁ ca pañcamo veda ucyate' (SB 1.4.20).
Scripture
Puranas
पुराण
The Puranas are the ancient memorial scriptures of Hinduism treating cosmology, cosmic cycles, genealogies, dynastic history and the glories of the gods; the tradition counts eighteen Maha-puranas and an equal number of Upa-puranas. In the processed verses: Suta has studied them as expounded by the masters (SB 1.1.6); they are known fully to Badarayana and the other sages (1.1.7); and the Srimad Bhagavata is itself a Maha-purana (1.1.2).
Śrīmad Bhāgavata Mahāpurāṇa 1.1.6 — Sanskrit Wikisource (pinned oldid=110172)
The ten characteristics: sarga, visarga, sthana, poshana, uti, manvantara, ishanukatha, nirodha, mukti, ashraya
'atra sargo visargash ca sthanam poshanam utayah, manvantareshanukatha nirodho muktir ashrayah' (SB 2.10.1); each defined at SB 2.10.3-7.