Add .dropboxignore directory to exclude folders without using selective sync

@projectdeliverypartners no that is not the functionality asked for by the OP, or I imagine most of the people in this thread as we have been discussing this for quite some time. What you are talking about is what the OP is referring to as select sync, and most of us are very well aware of it. It requires a whole process to be done on every device that you set up dropbox to sync on (now and in the future), and every folder/file that you want to not sync (again, now and in the future). The process with select sync is: sync dropbox, turn off dropbox, create the folder, use the select sync command on the folder to turn it off, add your files to the folder, turn on dropbox and resync. Not only is this mundane and sometimes unreasonable if dealing with a large number of devices and/or folders, but it is also not safe. If one folder on any device is not properly set to select sync then it will corrupt your entire sync across all devices and creates conflicts which must then each be cleaned up and the whole process repeated - for every device. This is why other services, such as github, have a .ignore file. 

Further, select sync, as is, creates other issues because it still goes into that folder and locally syncs everything which can create problems with specific files -- such as in here: https://www.dropboxforum.com/t5/Apps-and-Installations/Bug-quot-unable-to-sync-quot-a-file-that-is-in-an-ignored-folder/m-p/777269#M67577