JPG is the first thing I need (ie: copy of my ID card, ...).
PDF would be nice but I agree that this might blow the database for people not understanding what is happening in the synchro process.
Nevertheless, any file format would be really good as I may want to attach, for example, ssh private keys.
While this idea was here first, there is a related idea to allow attachments of any file type. I would recommend that this idea is deleted and instead you vote for the other idea here:
Attaching any kind of file:
Norman Bates commented
I agree with Josh. Until now it's possible to add .JPG as attachment. I wish it ble able to add .PDF to soon i the future. It's enough to support those two fileformat.
Honestly, allowing any file type would seriously bloat the database file as users would "upload" everything and anything. My opinion is that the information that needs to be stored within the database should be relevant to the credentials or information being stored - i.e. a PDF version of my passport, insurance policy, etc. However at the end of the day I could care less what types of files are allowed, as long as PDFs are included. ;)
Why not any file type?