Header file generated by a Microsoft C/C++ compiler; contains definitions of interfaces and identifiers generated by the #import directive; used in conjunction with a .TLI file to reconstruct compiled type library contents for use in C/C++ source code. NOTE: The #import directive generates both TLH and TLI files. For example, the command #import "mylib.tlb" generates the "mylib.tlh" and "mylib.tli" files from a .TLB file.