The mimetype for notes is "application/x-vnd.kolab.note". This is the specification of the body contents:
<?xml version="1.0" encoding="UTF-8"?>
<note version="1.0">
<!-- Common fields -->
<uid>(string, no default)</uid>
<body>(string, default empty)</body>
<categories>(string, default empty)</categories>
<creation-date>(datetime, no default)</creation-date>
<last-modification-date>(datetime, no default)</last-modification-date>
<sensitivity>(string, default public)</sensitivity>
{<inline-attachment>(string, no default)</inline-attachment>}
{<link-attachment>(string, no default)</link-attachment>}
<product-id>(string, default empty)</product-id>
<!-- Note specific fields -->
<summary>(string, default empty)</summary>
<background-color>(color, default #000000)</background-color>
<foreground-color>(color, default #ffff00)</foreground-color>
</note>See Section 4.1> for the description of the common fields