Sanskrit Transliteration Characters

[Krishna Desikachary]

Hello,   I have a two-fold question:   a) There is an internationally accepted set of extra chars that are included in Roman (Latin) script to transacribe Sanskrit texts in Roman script. Does a Unicode standard exist for these characters? Were these ever standardises even outside the realm of Unicode?   b) Are ther any public, or commercial fonts available that follow these standard.   I will be grateful to know answers to these questions - Thanks and regards - k>Desikachary