Manusmriti
भोःशब्दं कीर्तयेदन्ते स्वस्य नाम्नोऽभिवादने । नाम्नां स्वरूपभावो हि भोभाव ऋषिभिः स्मृतः ॥ १२४ ॥
saluting he should pronounce after his name the word bhoh; for the sages have declared that the nature of bhoh is the same as that of (all proper) names.
english translation
bhoHzabdaM kIrtayedante svasya nAmno'bhivAdane । nAmnAM svarUpabhAvo hi bhobhAva RSibhiH smRtaH ॥ 124 ॥
hk transliteration by Sanscript