A "thank you for joining" membership letter should include a personalized greeting to the new member. Use the member's first name in your salutation.• Complete and sign the Application Form. Once you have submitted the form, you will be contacted to set up a time and date for meeting. Boost your renewal rates with a foolproof membership renewal letter! Information and links to various college resources for college employees including faculty, staff and management. Your Registration Code is a unique code created for each vendor number and tenant number. You'll need your tenant number or vendor number. We have various applications and forms available on our web site for your convenience. You may complete an on-line application at the Contra Costa Human Resources Department at 651 Pine St., 2nd Floor, Martinez, CA 94553.