These cookies let our server know that you are continuing to visit our site. The OMB Memo 10-22 guidance defines our use of session cookies as “Usage Tier 1-Single Session.” The policy says, “This tier encompasses any use of single session web measurement and customization technologies.”</p> <p> <b>Persistent Cookies: </b>We use persistent cookies to differentiate between new and returning visitors to our site. Persistent cookies remain on your computer between visits to CISA websites for six months.