Library archive created by HotDocs, a digital form preparation application often used for insurance and legal forms; saves a collection of "clauses," which are text templates that can be inserted into a form; saved in a compressed .ZIP format.

HCL files are used with .HDL clause library files, which contain filename references to the clauses in the clause archive. Therefore, when opening an HDL that uses an HCL file, HotDocs extracts and decompresses each clause on the fly as it is needed by the application. Clause libraries and clause archives are saved to the following directory: \My Documents\HotDocs\Libraries\.