File extension ID or identification process refers to identifying what kind of information is located in a file with unknown or scrambled extension. Also there are lots of files with extensions which don’t really describe what kind of information is stored in the file. Examples of such extensions are DAT and BIN. To get understanding of what kind of information is stored in a certain file you need to use software like HEX editor or other kind of investigation techniques described in this site.
If you think you know software from which file originated you can try renaming file in question to have extension which is produced by that software and then try opening it. This may solve the issue.
Alternatively File extension ID=0402 could refer to file with extension ID. Files with extension ID could contain following information:
- ID file for Lotus Notes Server
- Domino Server ID file
- BluRay, DVD or CD file identification information
- AOL instant messenger Buddy identification file
In case of Domino Server and Lotus Notes Server ID files you need to have software noticed above installed to view ID files. Or you can try opening it with HEX editor (described in an article on this site) and see what exactly is stored inside.
In case of BluRay, DVD or CD identification file you can just open it with text editor to see what is inside. Typically such ID file just contains textual information about BluRay, DVD or CD disk.
AOL instant messenger Buddy ID file is just a renamed JPG or PNG file. So all you need to do to open it is to try renaming it to JPG or PNG and see if it opens in your image viewer or graphics editor.
Also File extension ID=0402 could refer to locale 0402 which is used by Windows operating system to identify Greek locale in Basic language collection. Below are possible combinations of Local ID:input locale.