IDLK Files

When you have an open InDesign document, there is an additional file with a similar name that magically appears in the same directory as the file you have open. For example, if you have opened a file named Chapter_1.indd, you’ll see a companion file named ~chapter_1~p965so.idlk in the directory. The tilde (~) in front of the name and the file extension .idlk tell you that this is an InDesign lock file. Its purpose is to prevent multiple users from simultaneously opening an InDesign file across a network. Instead, they’ll see an alert informing them that they do not have permission to open the document.

Don’t delete .idlk files—InDesign cleans up after itself. The files will evaporate when you save and close the open file. If InDesign should crash while a document is open, it won’t have time to delete the .idlk file, but just leave it anyway. InDesign will take care of the housekeeping the next time you open, save, and then close the file.