Rules for Sraddha - Verse 2-4

One who knows all the six Vedangas, who worships the three sacred fires at three sandhyas (morning, noon, and evening) and who offers libations with the three madhus (sugar, honey and ghee), the priest (of the family), nephew, daughter's son, father-in-law, son-in-law, maternal uncle, saintly Brahmin, particularly one who worships the five sacred fires, disciple, matrimonial relative and one who respects his parents—these are fit to be invited in Sraddha.