Nginx and sent cookies

Hi. I have a doubt about logging the sent cookies.
In the log_format I have the following: ’ … $sent_http_set_cookie
…’

In the program I am setting 2 cookies, but in the log it only appears
one of them:
v=VALUE; Domain=DOMAIN; Expires=Fri, 05-Jun-2015 13:16:47 GMT; Path=/

the key of the other cookie is “d”.

So, why isn’t the other cookie present in the loggin file?

Thanks in advance,
Tomas Zulberti