You can make any standard folder on your computer or other writable media into a cubby. This includes fixed or removable disk such as an external hard disk drive, USB stick (pen drive), Flash reader or similar, including NAS (Network-attached storage). For more information about syncing NAS devices, see Using NAS Devices with Cubby.
Are sub-folders included in a cubby?
Sub-folders are also included in your cubby. So for a folder called 2013 with a sub-folder for each month, each month will also be in the cubby and stay in sync.
Which folders can't be cubbies?
If you try to make a non-standard folder into a cubby, you'll see this error: "The folder you chose cannot be made into a cubby."
The folder must not meet any of the following conditions:
- Be a subfolder of an existing cubby
- Be the parent of an existing cubby
- Be on a read-only media - for example, a CD- or DVD-ROM
- Have a name that begins with a dot/period, like this: .folder_name_with_period
- Have a name longer than 255 characters or ending in a space
- Be a hidden, Windows or System folder or have one as a parent or among its children
- Windows folder: c:\Windows
- System folder: c:\Windows\System32\
- Be a Library or Applications folder or have one as a parent or among its children
Which files can't be synced?
That said, the following file and folder types will not be synced:
- Hidden or system (Windows)
- Invisible (Mac)
- Starting or ending with a dot/period, like this: .file_name_with_period
- With a name longer than 255 characters, ending in a space, containing an ASCII code below 32, or containing any of the following characters: : ? / \ " < > | *
- Named or starting with any of these prefixes before a dot: com0, com1, com2, com3, com4, com5, com6, com7, com8, com9, lpt0, lpt1, lpt2, lpt3, lpt4, lpt5, lpt6, lpt7, lpt8, lpt9, con, prn, aux, clock$, nul
Note: Synced files are saved without any changes to file extension or format. A doc stays a doc. An xls stays an xls.