The Number Three can be used for all auspicious occasions, as it is the Number of the Father of the Heavens, Dyo Pita or Jupiter !
The English Three is also the Sanskrit Three ,
Thrai Lokyam Bhavayantam, Trigunamayam idam, Thraiksharasaika Vachyam.
Three Eesnam AIkya Roppam Thribhirapi nigamairgeeya manaswaroopam
The Trilogy of Books of Eternal Law, Sanatan Dharma, Prasthana Trayee
Gita, Brahma Sutras & Upanishads
The Trilogy of Books of Holistic Medicine, Ayurveda, Brihat Trayee
Charaka Samhita, SUsrushaSamhita & Ashtanga Hridaya
The Trilogy of Books of Wisdom of the Heavens, Astrology, Jyotish Trayee
Brihat Hora Sastra, Brihat Parasaraa Hora & Ganitha NIrnayam
The Trilogy of Books of Shakteya Vedanta, Shakti Trayee
Devi Mahatmyam Devi Bhagavatam & Soundarya Lahari
Even though only two has been referred to as Fifth Veda by scholars.
Bhagavan Aurobindo’s Savitri
& Melpathur’s Narayaneeyam
( Panchama Vedamam Naryaneeyathal Melpathur Vazhtihya Param porule !),
most of them qualify for the Fifth Place !
Om Tat Sat