Content-Disposition: inline

I have recipes to filter out mails with attachment/html/etc., with info collected on this discussion list. Recently some well formated pure ascii (text) mails were filtered out for the line in header: Content-Disposition: inline I checked through some mails, and found mails that really have attachment/multipart have "filename=XXXXXX" on the same line. So I modified my recipe to catch: ^Content-Disposition: inline; filename= Is this acurate enough? What does "inline" represent anyway? (I know this is not a SmartList question but I searched on net ..., including the RFC rules, but failed to find any). Any knowledge sharing is appreciated. Thanks! Zhiliang