CANDLE 101: What it is, How it Works, and Why You Should Care

March 9, 2022

In 2021, Nlets processed 362,755,413 Department of Motor Vehicles (DMV) transactions over our system. As you can tell from that statistic, DMV data is one of the most crucial resources for the law enforcement community in their day-to-day interactions with the public. As the International Justice and Public Safety Network, Nlets is committed to making that data as useful and powerful as possible.  


Data Standardization 

One way that we seek to make data useful and powerful for our users is through data standardization. For anyone unfamiliar with the concept, start by understanding that what is easy for a human to read is often difficult for a data system to process. Data standardization frameworks (such as XML) bridge the gap between humans and the data system by structuring data so that it can be processed programmatically prior to being used by officers on the street. These kinds of frameworks are useful because data that can be consumed programmatically can be ran through data, threat, and other law enforcement analytics. If you want to know more about data standardization, you can read our Chief Information Officer’s article, “Your Complete Guide to XML” on our website.  


What is CANDLE? 

Another way that Nlets has been leading the community towards data standardization is with the creation of the Collaboration between AAMVA and Nlets for Drivers License Exchange (CANDLE) specification. CANDLE is an XML data standard for DMV transactions that was initially created in 2009 by a committee that consisted of members of the Nlets community and representatives from AAMVA. The standard created in 2009 is considered CANDLE 1.0, but it underwent revisions in 2012 (creating CANDLE 2.0) and most recently in 2022 (producing CANDLE 3.0). You can read about the changes most recently made to the standard in this blog.  


Improvements to Data Standardization 

The CANDLE committee will continue to meet as necessary to discuss ways the standard can be improved. To find these improvements, members of the committee will often look at DMV data that they have available internally in their states. Then, they often recommend updates to the CANDLE specification that will allow that data to be communicated out of state.  

Another improvement to data standardization comes from the work Nlets did as part of our DMV Parsing initiative. The DMV Parsing initiative is a subcomponent of our core system that takes non-standardized DMV data and transforms it into CANDLE standardized responses through user specific parsing functions. Developing this framework provided us insight into the types of data that are included in our incoming non-standardized responses that do not have a home in our CANDLE specification. Nlets then used that information improve our CANDLE 3.0 specification. 


The following are highlights of some of the updates that were added to the CANDLE 3.0 specification as a result of the last committee meeting. 


Communication Impairment 

In a traffic stop, one of the challenges an officer might face is a subject with a communication impairment. The subject, for example, might be hearing impaired. With the CANDLE 3.0 update, that information can now be included as part of a License or Vehicle Response.  


Emergency Contact Information 

Our CANDLE specification has always included a location for residence and primary contact information as part of a Driver’s License response. However, the specification has now been updated to include a place for Emergency Contact information as well. 


REALID Compliance 

As more states and citizens adopt REALID Compliant Drivers licenses, the committee felt it was important to communicate that information in the CANDLE specification itself, which led us to include a REALID Compliance indicator in CANDLE 3.0. 


ID Card 

Driver’s Licenses are not the only form of identification that officers encounter. Oftentimes, they must check non-driver ID cards. The specification for the Driver’s License Response has been updated to allow for ID card information. 


Registered Sex Offender 

Several states include information about if an individual is a registered sex offender in their Vehicle Registration responses. This has allowed officers to better patrol school zones and neighborhoods by being able to run tags of suspicious cars to check for sex offenders. With the changes in CANDLE 3.0, the specification for the vehicle registration response has been updated to allow for that information as well.  


For those interested in learning more about regarding the CANDLE specification, you can visit the following sections of our user guide: 

Vehicle Registration Transactions  

Driver License Transactions  

Driver History Transactions