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Why does Excel think CSV files are SYLK?

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up vote 8 down vote accepted

Your file probably starts with ID; or something similar.

If the first two characters of the file are uppercase ID Excel assumes it's an SYLK file type. If you want to keep the column name you can make the characters lower case or insert an apostrophe, ', as first character in a text editor before opening in Excel.

The problem goes back to at least Office 2003 and is still present in Office 2013.

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Yep, that was it. – Jonathan Allen Nov 23 '10 at 18:28
What an awful format specification. I've got a .csv file that begins with "IDNUM," and Excel isn't smart enough to read it as a CSV? Oy. – nmpeterson Sep 18 '12 at 14:29

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