Characters Disallowed in File or Folder Names

Zoom Web Management Console allows administrator to configure  a set of characters as illegal or disallowed in file or folder name. Import/Ingest with files with such names will fail. This list can be customized however read the caveats that apply.

Major consideration for disallowed characters in file is the cross-platform access of files across disparate operation systems.

Client OS caveat:

By default the set of invalid characters defaults to the ones that Mac, Linux & Windows OS do not allow in a path name. This ensures that if a path in the Zoom repository gets checked out on any client OS, creating a working copy file/folder of that name will work. Even though Zoom with Unicode support built-in can handle any file name character set, built-in OS applications like Windows Explorer, MacOS Finder will have issues.

Server OS caveat:


If services like Preview server, Archive manager, Auto Checkout run on an OS that disallows certain characters, ingesting these assets from a client OS that does allow such characters will cause file access to fail on the DAM server. Since Zoom allows range of OS deployment options for client & server, the disallowed character list must take this into account.

The path name validation happens on individual characters, prefixes and suffixes. You can edit the default settings through the Server Control Panel’s repository “Repository Settings” menu.

Disallowed Characters

Any character included in the above field will be disallowed in any new paths being created in the repository. This list is simply a list, and is NOT comma-separated. (If you include a comma in the list, it will be treated as an invalid character in path names)

For example, if the character “*” is in this list, then a path name like “Tulips * Roses.jpg” will be disallowed from import / rename operations.

  • Slashes (forward and backward) are never allowed in the path names irrespective of whether they are listed here or not.
  • Spaces in between characters are always allowed.
  • Spaces before or after path names are trimmed off.


It is strongly recommended that you leave the set of default invalid characters as is. If you have to remove certain characters from this disallowed list, please make sure that in your server and client operating systems or file systems, that character is valid in path names. For example, “*” is acceptable in a path name in MacOS whereas in Windows it is not. If you remove “*” from this list, and run your Zoom server on MacOS X Server, then you will be allowed to create paths containing “*”. However, if you try to checkout that asset in a Windows OS client or use a Zoom API/Service that accesses the assets on Windows OS, it will fail because Windows will not allow creation of such a path on its file system. Therefore, it would make sense to remove “*” from the list, if and only if you are 100% sure that all your client machines and your server run on MacOS systems.

File-system Specific Disallowed Characters

Operating System
File System
Microsoft Windows Windows NTFS / ? < > \ : * | ”  Also any character one can type using the Ctrl key. Review this note from Microsoft including file/folder name length limits.
Microsoft Windows FAT / ? < > \ : * | ” ^ Also any character one can type using the Ctrl key. Review this note from Microsoft  including file/folder name length limits.
Apple MacOS 9 HFS+ : / \ NUL character ‘\0’ as well. See Apple recommendation on best practices for file naming
Apple MacOS X HFS+ : / \ NUL character ‘\0’ as well. See Apple recommendation on best practices for file naming
Linux various FS / NUL character ‘\0’ as well.


More resources to review on file name characters:

Wikipedia article on filename

File naming conventions in Linux

Microsoft file Naming conventions

Prefixes and Suffixes

You can also configure to disallow a pre-defined set of prefixes and suffixes. These are entered as a list of comma-separated strings in the respective fields. By default no such exceptions are included.

For example, including “.b” in the prefix list will fail an import of path name “.backup-folder”; including “.bak” in the suffix list will fail the import of “”

Names Ending with Dot [on Windows machines]

Windows OS does not allow path names to end with dots. If you attempt to rename a file or folder in a Windows machine inside the Windows Explorer, you may notice that it results in the file or folder disappearing from the view, and on clicking refresh the file or folder would show up once again with its original name (without the dot at the end). Attempting to rename on command line or programmatically, also results in failure, with or without explicit message about the outcome of the operation. Because of this limitation on Windows, we recommend that the Zoom server also enforce the same rule.
To achieve this, place the dot character in the field marked as “Suffixes Disallowed in Path Names” in “Repository Settings” (See screenshot above). You will need to restart the Zoom server for this rule to take effect. 

Names Containing Control Characters

You can add specific control characters in the list of disallowed characters too. But keep in mind, that entering the characters is only possible if you edited the server.xml file directly using an editor that supported entering the control codes. For example, Notepad++ in Windows (with Show Symbols option enabled) will let you enter control characters, by holding ALT key and typing the number code in the numeric keypad. In a Mac, you may have to use the Option key with the number combination. Once you enter the control character in the server.xml file, be sure to save it, and then restart the server for the rule to take effect.

Leave a Comment