This article concerns https://hbr.org/
HBR.org Uses Secure Cookies
An HTTP cookie (also called web cookie, Internet cookie, browser cookie or simply cookie), is a small piece of data sent from a website and stored in the user's web browser while the user is browsing. Every time the user loads the website, the browser sends the cookie back to the server to notify the user's previous activity. Cookies were designed to be a reliable mechanism for websites to remember stateful information (such as items added in the shopping cart in an online store) or to record the user's browsing activity (including clicking particular buttons, logging in, or recording which pages were visited in the past). Cookies can also store passwords and form content a user has previously entered, such as a credit card number or an address.
A secure cookie can only be transmitted over an encrypted connection (i.e. HTTPS). This makes the cookie less likely to be exposed to cookie theft via eavesdropping. To accomplish this goal, browsers which support the secure flag will only send cookies with the secure flag when the request is going to a HTTPS page. Said in another way, the browser will not send a cookie with the secure flag set over an unencrypted HTTP request.