What is a CSL file?
A Corel Symbol Library (CSL) file is a library of symbols used within CorelDRAW software. It stores symbols that can be used in other files. CSL files can be stored locally or on a network to let them accessible for easy deployment and management. These are saved with the CorelDRAW file along with all the symbol instances used within the document.
CSL File Format
CSL files are saved in CorelDRAW proprietary file format. Being a collection of symbols, the symbols inside a CSL file can be imported and added to drawings in a project.