"A SYLK file is a text file that begins with "ID" or "ID_xxxx", where xxxx is a text string. The first record of a SYLK file is the ID_Number record. When Excel identifies this text at the beginning of a text file, it interprets the file as being a SYLK file. Excel attempts to convert the file from the SYLK format, but is unable to because there are no valid SYLK codes following the "ID" characters. Because it cannot convert the file, Excel generates the error. "
(despite this being a knowledge base article for Excel on the Mac, this was on a PC)
Wikipedia is silent about the vaginal dryness, but tells me about Sylk, a character from the movie Glitter.
Hmm. Sylk. Glitter. Once again, the jokes almost write themselves :-)