The File extensions frame allows you to define the extensions used for MetaTexis documents and for the cleaned/final version. While the white text boxes allow you to define the extensions the grey boxes below display a preview (the sample languages are "English (US)" and "French (France)".
For the language identifiers you can use the following placeholders:
| 
       Placeholder  | 
    
       Explanation  | 
    
       Result  | 
| 
       {SL}  | 
    
       Source language: ISO2 language  | 
    
       EN  | 
| 
       {SR}  | 
    
       Source language: ISO2 region  | 
    
       US  | 
| 
       {SLR}  | 
    
       Source language: ISO2 language and region  | 
    
       EN-US  | 
| 
       {TL}  | 
    
       Target language: ISO2 language  | 
    
       FR  | 
| 
       {TR}  | 
    
       Target language: ISO2 region  | 
    
       FR  | 
| 
       {TLR}  | 
    
       Target language: ISO2 language and region  | 
    
       FR-FR  | 
Note: When you enter a file extension make sure to not use characters that are not allowed for file names in Windows. MetaTexis will automatically delete any characters not allowed.