add reference to proc(5)
diff --git a/libbb/procps.c b/libbb/procps.c
index 436905c..10f2ff5 100644
--- a/libbb/procps.c
+++ b/libbb/procps.c
@@ -71,6 +71,7 @@
 			continue;
 		bb_getpwuid(curstatus.user, sb.st_uid, sizeof(curstatus.user));
 
+		/* see proc(5) for some details on this */
 		strcpy(status_tail, "/stat");
 		n = read_to_buf(status, buf);
 		if(n < 0)