Dear Harry,

I'm not entirely sure that I made my point clear. I tried and have a look at the ISO-15919 standard online and realized I'd have to buy it to read the complete version. I have no intention in the foreseeable future to buy the whole ISO-15919 standard and read it through, but I guess it doesn't deal entensively with manuscript transcription. Any standard can be improved and I am sure that the ISO-15919 does not provide any clue as to how to transliterate the countless symbols that occur in South Asian manuscripts. You can get a fair idea of how many and how different they are in the various South Asian manuscript traditions by browsing Katrin Einicke's Korrektur, Differenzierung und Abkürzung in indischen Inschriften und Handschriften, Wiesbaden, Harrassowitz, 2009 (and in my personal experience, this work covers only a part of the symbols actually used in Sanskrit manuscripts). I also think that the ISO-15919 cannot possibly be exhaustive and all-encompassing, because it cannot cover all possible aims of transcription.

I am quoting and pasting the remarks provided by Prof. Witzel in the useful link you provided:

''The question is which ``norm`` to follow.''

Exactly this is the point. Often we normalize and bluntly follow Paninian rules even for Sanskrit texts that sometimes were clearly composed and written in non-Paninian Sanskrit.

''Prof.  v. Simson wrote:

But since the scribes are not consistent in their use of sandhi, I

think it is best to standardize the orthography and to follow Panini's
rules as far as sandhi is concerned. This makes it also easier for the
user of your edition. You may describe the actual practice of the scribes
in your introduction or you can give the writings of the manuscripts in
the critical apparatus. <<<''

Alas, sometimes scribes solved the sandhi to mark word boundaries in manuscripts that probably had didactical purposes. What shall we do in such cases? If we normalize the sandhi, then this information is lost (unless we note it in the introduction). We even go as far as to normalize the doubling of consonant after repha, even though this optional orthography is allowed by Panini (8.4.46) and it actually occurs very often in manuscripts. Why do we do that? Here is the reason, with the counter reason why we shouldn't do it, again in the words of Prof. Witzel:

"This is reasonable practice. However, I think the this practice *is* the
problem. At any rate, the case is more complicated. Once you start
comparing MSS from various areas of medieval India you notice clearly
defined local styles: the Kashmirians have one ``orthography`` of
Sanskrit, the Newars of the Kathmandu valley another, the Gujaratis,
Oriyas, Tamils, Nambudiris  still another, and so on...  Apart from
occasionl remarks (e.g. : this is Dravidian ``ra`` for  vowel ``r``) the
problem has hardly been noticed. (I think I have referred to it here and
there in articles on the Paippalada Atharvaveda; or see Lubotsky in IIJ
25 for Maitrayani Samhita /Gujarati practise which is surprisingly
different from what we learn  in school; cf. also Prof. Rao`s example of
pronunciation of   vowel R in sandhi ).

You write the following remark:

 To my mind the problem is that if you can't use a transliteration
standard to prepare a diplomatic transliteration then there is
something wrong with that transliteration standard.  Surely thats the
purpose of a transliteration standard. Note that the  rule for
normalizing anusvaras to class nasals is a "required rule" and not a
recommendation or option.  As you pointed out the normalization of
nasals is bad practice for transcribing manuscripts.  The
normalization of nasals  was pointed out as a problem in editing
manuscripts about 20 years ago on this list:

I think you are mixing up levels, because editing is one thing, and preparing a diplomatic transcription is another. Moreover, if a standard is not useful and creates more problems that it solves, then there is clearly a problem, in this I totally agree with you. However I also do not believe that the purpose of this standard was to provide a full guide as to how to prepare a diplomatic transcription of manuscripts from all South Asian manuscript traditions. In fact, it provides a standard to transliterate mainly Devanagari--and related Indic scripts (and this loose definition is already problematic). Does the standard provide a rule for distinguishing between siromatra and prsthamatra vowels? Then again, why should it?

I think that your question opened a can of worms, and I have to thank you a lot for having asked it.

Best wishes,

Camillo