The Harvard-Kyoto Convention[1] is a system for transliterating Sanskrit and other languages that use the Devanāgarī script into ASCII.
[citation needed] Prior to the Unicode era, the following Harvard-Kyoto scheme[3] was developed for putting a fairly large amount of Sanskrit textual material into machine readable format without the use of diacritics as used in IAST.
For the consonants, the differences to learn are: compared to IAST, all letters with an underdot are typed as the same letter capitalized; guttural and palatal nasals (ṅ, ñ) as the corresponding upper case voiced plosives (G, J); IAST ḷ, ḻ, ḻh are quite rare; the only transliteration that needs to be remembered is z for ś.
The vowels table, the significant difference is for the sonorants and Anusvāra, visarga are capitalized instead of their diacritics.
Sanskrit text encoded in the Harvard-Kyoto convention can be unambiguously converted to Devanāgarī, with two exceptions: Harvard-Kyoto does not distinguish अइ (a followed by i, in separate syllables, i.e. in hiatus) from ऐ (the diphthong ai) or अउ (a followed by u) from औ (the diphthong au).