Postgresql coding conventions

Hi,
I have noticed two different coding conventions being followed in
postgres code base.

See e.g. function names in syslogger.c

static void set_next_rotation_time(void);
static void sigHupHandler(SIGNAL_ARGS);

and variable names in the same file

int bytes_in_logbuffer = 0;
char *currentLogDir;

Chapter 46 of the documentation does not say much about variable or
function naming.

While writing code or reviewing a path are we supposed to consider the
camel cased names correct or the under-score separated names correct?

Regards
Abbas
www.enterprisedb.com