Can files with yellow exclamation be erased?



Hello, I'm the IT guy in my work and I noticed that Owncloud shared folders have some "only-read" and hidden files that are like(I imagine) temp files for the ones that the program syncs. The problems is that there are like 6 of these hidden files for each file even if it's a simple two lines document, this "temp" files(I assume) have the yellow exclamation and obviously are not part of the sync but I want to know if I can erase some or even all of them.


The yellow exclamation mark just means that the file are not synchronized because they are ignored for one or another reason. Usually because their name matches a pattern in the ignore list. Some of them may not be related to ownCloud at all, they are just there because of some other application.
There is also al the conflict files. They have "conflict" in their name, and can be removed if you don't care about their content. There is also temporary files of partially downloaded content. They should be removed automatically anyway. You can remove safely these file, it just mean that they will be re-downloaded.

But you must not remove the .csync_journal.db file. This file is critical for the synchronization algorithm. That is the only file that you should not delete.