Why is some text in PDF to SVG output uppercase/lowercase?

[Support]

Q:

I have tested PDFTron PDF to SVG product and it looks really
interesting to use as a possible solution. However, in some pages the
demo turns some letters into Uppercase.
I read in the FAQ that the demo takes away some letter, which I
understand. But why does the program turn some letter in uppercases?

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A: It is possible that the PDF has a corrupt ToUnicode Cmap. As a
workaround, disable Unicode mapping during PDF to SVG conversion (i.e.
'--nounicode'). Assuming that you are embedding SVG fonts, this will
accurately preserve text (provided that your browser supports SVG
fonts – which is sometimes not the case) .