[the_mitsuhiko]

I don’t know the situation in India but brokers in Austria and Germany do the same. The law does not stipulate the format but PDF is what everyone uses. I assume it’s because it can be signed and archived and will outlast pretty much anything. You need to keep these for 7 years.

[mr-karan]

Yes, in India, the law mandates that ECNs (electronic contract notes) need to be digitally signed with a valid certifying authority. While it's true that XML/docx/xls files could also support digital signatures, but I think PDFs are prevalent and also allow clients to verify this on their end, quite easily.