The Devanagari transliteration reference article from the English Wikipedia on 24-Apr-2004
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Devanagari transliteration

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In the traditional Devanagari transliteration scheme, many words and names have a final "a" appended to them, derived from the original Sanskrit. This final vowel is generally not pronounced in modern Hindi and some other Indian languages. The final "a" may however be pronounced and used in other modern Indian languages. In more recent transliterations from Hindi, the final "a" is often omitted, resulting in alternative spellings for many Sanskrit words and names. In these cases, Wikipedia uses the spelling with the appended "a", as it continues to be more common in writing even though it is inconsistent with Hindi pronunciation (e.g. Rama/Ram, Mahabharata/Mahabharat, Siva/Shiva/Shiv, etc).

Where the letter "h" appears after a plosive consonant in Devanagari transliteration, it is always pronounced as a distinct sound (the aspiration), and never "swallowed" or combined with the preceding consonant.