Kautilya's Arthashastra 2.10.5

2.10.5

jātiṃ kulaṃ sthānavayaḥśrutāni karmarddhiśīlāny atha deśakālau /[ś]
yaunānubandhaṃ ca samīkṣya kārye lekhaṃ vidadhyāt puruṣānurūpam //[ś]

Having paid sufficient attention to the caste, family, social rank, age, learning (sruta), occupation, property, character (síla), blood-relationship (yaunánubandha) of the addressee, as well as to the place and time (of writing), the writer shall form a writ befitting the position of the person addressed.