Enumerations in FIX

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1

Imported from previous forum

2

[ original email was from David Adams - Dave.Adams@msdw.com ]
Hi,

This more a curiosity than anything else, but does anyone know the reason why some enumerations are 0 based (for e.g. tags 39, 59, 63) whilst others are 1 based (for e.g. tags 18, 40, 54)?

Many thanks,
Dave.

3

[ original email was from Dean Kauffman - dean.kauffman@tradeweb.com ]
> Hi,
>
> This more a curiosity than anything else, but does anyone know the reason why some enumerations are 0 based (for e.g. tags 39, 59, 63) whilst others are 1 based (for e.g. tags 18, 40, 54)?
>
> Many thanks,
> Dave.
>

Dave,

I suspect there’s a bit of interesting history at play here, but in general I sense that the zero enum values are true defaults that could be omitted or that represent virginal status:
(39)OrdStatus=New
(59)TimeInForce=Day
(63)SettlmntType=Regular

The enumerations that start with 1 have an implied 0 value of "no action" if the field is omitted or else the fields are required:
(18)ExecInst [an array of special actions]
(40)OrderType [required: no default value]
(54)Side [required: no default value]