EMA C++ RDM Usage Guide : 5 Dictionary Domain : 5.5 Field Dictionary : 5.5.2 Field Dictionary File Format : 5.5.2.5 Custom FIDs
 
5.5.2.5 Custom FIDs
There are a couple of recommendations for custom Field IDentifiers:
 
Table 43: Marketfeed to Rssl Wire Format Mappings in RDMFieldDictionary  
Field Type
LeNGTH
RWF Type
RWF LEN
NOTES
PRICE
17
REAL
9
Real can represent values with fractional denominators, trailing zeros, or up to 14 decimal positions.
INTEGER
15
INT
8
Signed integer value that has one sign bit and 63 value bits.