---
title: "Are there good and bad characters for things like filenames, metadata, and collections?"
date: "2025-01-09T14:09:13+00:00"
summary:
image:
type: "page"
url: "/acquia-dam/are-there-good-and-bad-characters-things-filenames-metadata-and-collections"
id: "8af86a75-f976-480c-a82e-5db464a8abd4"
---

Different components in Acquia DAM have specific character restrictions. The following guidelines separate restrictions by component type:

### Filenames

Best practices for filenames:

1.  Use dashes (-) or underscores (\_) to separate words.
    
2.  Keep filenames to 27 characters or less (excluding extension) for optimal display.
    
3.  Limit filename length to a maximum of 128 characters.
    
4.  Ensure file extensions are present to process and match assets during imports and exports.
    

Avoid these in filenames:

*   Spaces at the start or end
    
*   Spaces before the file extension
    
*   Periods at the start or end
    
*   Files that end with .appl
    
*   The following characters: < > : " / \\ | ? \* , + % # ( ) \[ \] { }
    
*   DOS-reserved filenames: AUX, CLOCK$, COM1-COM9, CON, LPT1-LPT9, NUL, PRN
    

### Collections and categories

Avoid these characters in collection and category names:

*   < > : " / \\ | ? \* , + % # ( ) \[ \] { }
    
*   Spaces at the start or end
    

### Metadata

Character restrictions for metadata fields:

*   Avoid the following characters, which can cause issues with search or imports: < > : " / \\ | ? \* , + % # ( ) \[ \] { }
    
*   System trims spaces at the start and end.
    
*   System can strip some special characters during process cycles.
    

### General restrictions

The following items lack support across any component:

*   Certain Latin, Asian, and Arabic characters
    
*   Advanced mathematical symbols
    
*   Unicode characters that can cause system conflicts
    

Note

For bulk uploads, the total file path length (including filename) must not exceed 1,024 characters. This limit includes internal system path components (such as /imports/<customername>/<jobid>/), which vary by customer. In practice, keep file paths well under this limit to account for these system-generated path segments.