NameValueLength ( MQLONG)

The length of the corresponding NameValueData field

This specifies the length in bytes of the data in the NameValueData field. NameValueLength must be a multiple of four.

Note: The NameValueLength and NameValueData fields are optional, but if present they must occur as a pair and be adjacent. The pair of fields can be repeated as many times as required, for example: 

length1 data1 length2 data2 length3 data3

Because these fields are optional, they are omitted from the declarations of the structure that are provided for the various programming languages supported.