The importToList (SOAP API) documentation says and shows an example indicating that the lead data to be imported is in the form of comma-separated fields, like this:
<stringItem>Awesomesauce,Developer,Code Slinger,Marketo,dawesomesauce@marketo.com</stringItem>
I assume there must be some quoting convention in effect (to handle a field whose data itself contains a comma), but I didn't have any luck uncovering that convention. How do we ensure that a stray comma in a data field is accurately handled as field content rather than as a field separator?