The affix ṭhac is optionally added to a word of more than two syllables being the name of a human being, as an expression of compassion or of courtesy joined with compassion.,
In the alternative we have कन् also. As अनुकम्पितो देवदत्तः = देविकः (देवदत्त + इक = देव + इक) 5.3.83. When कन् is added there is no shortening of the base, as देवदत्तकः ॥ Similarly यज्ञिकः or यज्ञदत्तकः ॥
Why do we say बह्वचः 'after a polysyllable?' Observe दत्तकः, गुप्तकः ॥ Why do we say 'being a Man-name'? Observe मद्रबाहुकः, भद्रबाहुकः which are epithets and not Proper Nouns (मद्रौ बाहू यस्य); or these are names of quadrupeds.,