The following functions are built-in to the DDS "fmt" specifications:

Function         Description
------------     ------------------------------------------
axis_size(a)     specifies the size of the axis as defined
                 by "a" which can either be the axis name
                 ("x", "Vp", ...) or number (1, 2, ...)

ident(field)     specifies a name for a field; this can be
                 used when a field name may contain non-
                 alphnumeric characters (eg. ident("SHT-X"))

defn_value(d,n)  Pull a value from a Definition name,n,
                 from Dictionary, d;
                 eg. defn_value("hist:","delta.x")