Recently for my college magazine I had to troubleshoot the Malayalam section.
A friend collected the Malayalam articles from various students of the college and sent to someone in Kerala to type them out.The stupid typist in Kerala typed that using some software in an ascii font.
You have heard of arial, times new roman, etc. These are fonts that make English letters come beautifully. Now, imagine we replace the symbol 'A' in Times New Roman and keep malayalam letter അ there. Then, whenever you type 'A' in that modified font, you'll get the Malayalam character. But if you change the font you'll get 'A' itself. This is how an ascii font works.
So this typist had typed the entire thing such that it works only with Ambili font.
So I had to manually replace in a word document the following:
ല് to ൽ
ണ് to ണ് (they were the same)
ന് to ൻ
ള് to ൾ
ര് to ർ