I found a defective rule in the squid.rules file
it has an error plus a missleading classification text and impact description
here is a sample of the log

r11323: Squid Parent: child process 10216 exited due to signal 6

here is what the rule currently is:

# No log sample; please submit
regex=Squid Parent: child process (\d+) exited; \
 classification.text=Proxy stopped; \
 id=1808; \
 revision=1; \
 analyzer(0).name=Squid; \
 analyzer(0).manufacturer=www.squid-cache.org; \
 analyzer(0).class=Proxy; \
 assessment.impact.severity=medium; \
 assessment.impact.type=other; \
 assessment.impact.description=Squid (pid $2) exited; \
 target(0).node.name=$1; \
 target(0).process.name=squid; \
 target(0).process.pid=$2; \
 last

here is what it should be:

#r11323: Squid Parent: child process 10216 exited due to signal 6
regex=Squid Parent: child process (\d+) exited due to signal (\d); \
 classification.text=Proxy child process stopped; \
 id=1808; \
 revision=2; \
 analyzer(0).name=Squid; \
 analyzer(0).manufacturer=www.squid-cache.org; \
 analyzer(0).class=Proxy; \
 assessment.impact.severity=low; \
 assessment.impact.type=info; \
 assessment.impact.description=A Squid child process (pid $1) exited after reciving a signal $2; \
 target(0).process.name=squid; \
 target(0).process.pid=$1; \
 last