You can apply a "Use File-Templates" when creating "New Files" by pre-defining a header, which will be inserted at the beginning of a file each time you create a new one when using the "file create new" functionality in the "IBM/Informix 4GL Development" perpective.
To apply a individual header, text can be can be added to any provided keyword template:
In the Eclipse IBM/Informix 4GL Development perspective open a file.
In Eclipse go to Window > Preferences >Eclipse4GL > File Templates.
Choose a provided file type from the upper list.
Enter a text (usually a comment) in the edit section.
Click Apply / Apply and Close.
Activate option in preferences
Make sure you have activated "Use File-Templates when creating New Files" in Preferences if you want to use them by deafult.
Example of a keyword code template header extension after using the file new crreation functionality ...