Excact dataset format specification

Is the exact dataset upload format documented somewhere ?

I know for sure it’s UTF8 (I work with datafiles regularly).

I need specifications for:

  • Limit on size (columns x rows)
  • UTF8 plain or UTF8 signature
  • quoted fields or not quoted fields ?
  • field separator expected ?
  • line terminator expected ?

It would be great if the dataset format could be uploaded as a JSON array.