What's the meaning of “0-big number” in syslog.h?

Question

I'm chinese.I'm reading syslog.h,and i find a term "0-big number" which i can't understand.I can understand the hole paragraph meaning,but i'm still curious about the term "0-big number",could anybody explain the term?

/*
* priorities/facilities are encoded into a single 32-bit quantity, where the
* bottom 3 bits are the priority (0-7) and the top 28 bits are the facility
* (0-big number).  Both the priorities and the facilities map roughly
* one-to-one to strings in the syslogd(8) source code.  This mapping is
* included in this file.

/* facility codes */
 #define LOG_KERN    (0<<3)  /* kernel messages */
 #define LOG_USER    (1<<3)  /* random user-level messages */
....
*/

Answer 1

The author just decided to call 28 set bits ( 2^28 - 1 ) a big number instead of writing it out. So it's not a term but means zero to big number .