own manual page.
Variable names (I<vname>) must be made up strings of the following characters
-C<A-Z, a-z, 0-9, _> and a maximum length of 255 characters.
+C<A-Z, a-z, 0-9, _, -> and a maximum length of 255 characters.
When picking variable names, make sure you do not choose a name that is
already taken by an RPN operator. A safe bet it to use lowercase or
} rpn_cdefds_t;
#define MAX_VNAME_LEN 255
-#define DEF_NAM_FMT "%255[_A-Za-z0-9]"
+#define DEF_NAM_FMT "%255[_A-Za-z0-9-]"
/* limit imposed by sizeof(rpn_cdefs_t) and rrd.ds_def.par */
#define DS_CDEF_MAX_RPN_NODES (int)(sizeof(unival)*10 / sizeof(rpn_cdefds_t))