Those picky little details in gas system design – elements that look like a key, sound like a key, but they are NOT keys!

Good Afternoon!  This is becoming a series of blogs on the topics of details in gas system design and, in particular, the nomination key.  Look at the two previous blogs to get up-to-speed on this discussion.

The first one, talking about composite data elements, can be found at:

The second one, talking about the nomination key, can be found at:

Today we’re going to talk about two NAESB data elements that are often mistaken to be associated with the nomination key. We’re going to stir the pot and talk about the nomination dataset’s Activity Code and Nominator’s Tracking ID (NAESB WGQ Standard 1.4.1, Version 3.0,, password protected).  Neither of these is a key to a nomination and neither is part of the key to a nomination but a lot of people try to use them as a key.

The Activity Code is best described as an alias for part of the nomination key.  NAESB does not define the data elements that the Activity Code represents, therefore one pipeline may see it as representing a contract + path while another pipeline may include other, non-mandatory elements in their definition of Activity code and a third pipeline may use the Activity Code as the entire nomination key.  It is up to the individual pipeline to determine which elements it uses to comprise the Activity Code.  The Activity Code was created in the early days of the nomination dataset when two pipelines offered services where the shipper could provide an alias plus dates and quantities in order to nominate without having to provide the whole string of nomination data.  One of those pipelines included the Package ID data element as part of the Activity Code and the other didn’t.  A few other pipelines picked up this feature, with varying methods of implementation, when their shippers expressed appreciation of the feature.  Today, with all of the web technologies that are available, some of those same pipelines have abandoned the Activity Code because they can use copy functions and other tools to give the shipper the same level of service.

The Nominator’s Tracking ID was designed for EDI (Electronic Data Interchange) transactions as a method of communicating error- and warning-messages related to a specific nomination line item in a dataset transmission that might contain many nominations.  The Nominator’s Tracking ID is only valid for the lifecycle of the initiating nomination and its corresponding validation message within an EDI dataset pair.  After that, the Nominator’s Tracking ID has no value.  If a shipper sends an update to the same nomination line item in a later dataset, the shipper may use the same tracking ID or a completely different tracking ID.  This information is not validated by the pipeline because the tracking ID means nothing to the pipeline.  Likewise, the shipper can re-use the same set of Nominator’s Tracking IDs every time they send a new nomination file because the tracking ID means nothing beyond the validation of that file.

It appears that often, when a developer looks at the Nomination dataset and sees these two elements they interpret one or the other to be “the key they’ve been looking for” in place of constructing a nomination key out of that long list of data elements we discussed in the previous blog.  Unfortunately, that won’t work and will, soon, cause other problems to arise.

Avoid the problems.  Study the datasets.  Understand the key.  Have fun with this puzzle.

Oh – and for those of you who don’t know – the book is out on September 15th!  Amazon now has it listed for pre-order – or you can buy one here on the website!  Woohoo!

2 thoughts on “Those picky little details in gas system design – elements that look like a key, sound like a key, but they are NOT keys!

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