# Sequence Reset

**URL:** <https://forum.fixtrading.org/t/sequence-reset/12940>\
**Category:** General Q&A\
**Tags:** imported, 44-changes, xid\_165491\
**Created:** [April 5, 2011, 1:03pm UTC](https://forum.fixtrading.org/t/sequence-reset/12940 "2011-04-05T13:03:42Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![larsmattsson\_x](https://avatars.discourse-cdn.com/v4/letter/l/90db22/32.png) [@larsmattsson\_x](https://forum.fixtrading.org/u/larsmattsson_x)\
**Post date:** [April 5, 2011, 1:03pm UTC](https://forum.fixtrading.org/t/sequence-reset/12940/1 "2011-04-05T13:03:42Z")

</div>

Imported from previous forum

---

<div class="post-metadata">

**Author:** ![larsmattsson\_x](https://avatars.discourse-cdn.com/v4/letter/l/90db22/32.png) [@larsmattsson\_x](https://forum.fixtrading.org/u/larsmattsson_x)\
**Post date:** [April 5, 2011, 1:03pm UTC](https://forum.fixtrading.org/t/sequence-reset/12940/2 "2011-04-05T13:03:42Z")

</div>

Hello,

When reading the Specification there is two different sections that explains how message recovery works.

First:  
SESSION PROTOCOL  
Message Recovery -  
Upon receipt of a Resend Request, the resender can respond in one of three ways:

1. retransmit the requested messages (in order) with the original sequence numbers and PossDupFlag set  
to “Y” except for the administrative messages (listed below) which are not to be resent and which  
require a SeqReset-GapFill (#2)
2. issue a SeqReset-GapFill with PossDupFlag set to “Y” message to replace the retransmission of  
administrative and application messages

Then there is the second part that explains the same thing but with diffrent fields filled in:  
Sequence Reset (Gap Fill) -

Gap Fill mode  
Gap Fill mode is used in response to a Resend Request when one or more messages must be skipped over for the  
following reasons:  
• During normal resend processing, the sending application may choose not to send a message (e.g. an aged  
order).  
• During normal resend processing, a number of administrative messages are skipped and not resent (such as  
Heart Beats, Test Requests).  
Gap Fill mode is indicated by GapFillFlag (tag 123) field = “Y”.

So should you reject a message with GapFillFlag but without the possDupFlag or should you accept it? And what part of the documentation is the “correct” part?