# Header & Trailer

### Standard Header <a href="#standard-header" id="standard-header"></a>

<table><thead><tr><th width="81">Tag</th><th width="189">Name</th><th width="105">Data Type</th><th width="78">Req’d</th><th>Description</th></tr></thead><tbody><tr><td>8</td><td>BeginString</td><td>String</td><td>Y</td><td>Must be <code>FIXT.1.1</code> for FIX 5.0 protocol version.<br>Must be the first field in the message.</td></tr><tr><td>9</td><td>BodyLength</td><td>Length</td><td>Y</td><td>Must be the second field in the message.</td></tr><tr><td>35</td><td>MsgType</td><td>String</td><td>Y</td><td>Message type.<br>Must be the third field in the message.</td></tr><tr><td>34</td><td>MsgSeqNum</td><td>SeqNum</td><td>Y</td><td>Message sequence number.</td></tr><tr><td>49</td><td>SenderCompID</td><td>String</td><td>Y</td><td>Company identifier as allocated by NDAX</td></tr><tr><td>56</td><td>TargetCompID</td><td>String</td><td>Y</td><td>Receiver FIX session identifier.<br>Always <code>INDAX</code>.</td></tr><tr><td>50</td><td>SenderSubID</td><td>String</td><td>N</td><td>A text field to indicate the name or identifier of the person or entity submitting the trade.</td></tr><tr><td>142</td><td>SenderLocationID</td><td>String</td><td>N</td><td>ISO identifier of message originator's location.</td></tr><tr><td>1128</td><td>ApplVerID</td><td>String</td><td>N</td><td>Indicates the protocol being used in this message.<br>Supported values:<br><code>9</code> = FIX50SP2<br></td></tr><tr><td>57</td><td>TargetSubID</td><td>String</td><td>N</td><td>Identifies specific trading unit. Conditionally required for Application messages.<br>Always <code>ZERO</code>.</td></tr><tr><td>52</td><td>SendingTime</td><td>UTCTimestamp</td><td>Y</td><td>Time of message transmission.</td></tr><tr><td>369</td><td>LastMsgSeqNumProcessed</td><td>SeqNum</td><td>N</td><td>The last <code>MsgSeqNum (34)</code> value received and processed.<br>Used to detect a backlog.</td></tr></tbody></table>

### Standard Trailer <a href="#standard-trailer" id="standard-trailer"></a>

<table><thead><tr><th width="74">Tag</th><th width="116">Name</th><th width="116">Data Type</th><th width="84">Req’d</th><th>Description</th></tr></thead><tbody><tr><td>10</td><td>CheckSum</td><td>String</td><td>Y</td><td>Checksum of message and end of message delimiter.</td></tr></tbody></table>