Sequencial Order For Messages

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Imported from previous forum

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Do fix orders have to go in style - Header/Message/Trailer - or can they be sent numerically - does the protocol state how it should be sent?

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Yes, the protocol does state how messages are to be constructed. Please refer to “FIX ‘Tag=Value’ SYNTAX” section’s “Message Format” in Volume 1 of the FIX 4.3 spec.

> Do fix orders have to go in style - Header/Message/Trailer - or can they be sent numerically - does the protocol state how it should be sent?
>

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[ original email was from Ryan Pierce - rpierce@taltrade.com ]
> Do fix orders have to go in style - Header/Message/Trailer - or can they be sent numerically - does the protocol state how it should be sent?

There are a few general rules about ordering:

  1. All header fields must come before all body fields, which must come before all trailer fields.

  2. Within the header and the trailer, there are certain requirements. For instance, in the header, BeginString, BodyLength, and MsgType must be the first three fields, in that order. And in the trailer, CheckSum must appear last.

  3. If sending a repeating group, all fields in the repeating group must be specified for each repetition in the order listed in the spec.

Other than that, you can order the fields however you choose.

Note that this is NOT true of FIXML. The FIXML DTD requires elements appear in the order listed in the DTD.