Bug#797883: release-notes: Wheezy to Jessie: in Squid helper name changes break configuration
-- System Information:
Debian Release: 8.1
Helper names are not the same in squid3 3.1.20 (Wheezy) and squid3 3.4.8 (Jessie). When you upgrade, squid won't start until you change your configuration file. See http://www.squid-cache.org/Versions/v3/3.2/RELEASENOTES.html#ss2.6.
I think it should mentioned in chapter 5 ("Issues to be aware of for jessie") of the documentation.