How do I fill this out? Clark requires suppliers to receive Purchase Orders and submit Invoices electronically either via Coupa Supplier Portal (CSP) and cXML. Transmission.Additionally, the Subcontractor shall fill out and sign the lien waiver form provided by. Clark's safety expectations and requirements are among the most stringent in the industry. The subcontractor's guide to working with Clark Construction, including their history, how to prequalify, payment tips, and more. To fill out this document, first gather all required information such as your company details and insurance information. If you are interested in one of our face-to-face learning sessions, contact us at (330) 978-3157, or fill out the Request Form. Application Forms, Do I Need a Permit? Thank you for your interest in ClarkDietrich. We're ready to supply you with the information you're looking for.