For those actually interested, I'm never quite sure who just wishes to argue and who might find information interesting...
An NFA (National Firearms Act) or Class III item (there are many names and words used) is an Item described within the NFA as prohibited unless you go through a lengthy process to get a stamp or license for the item (from short barreled weapons, to automatic weapons made before 19-something, to silencers, etc.). In many states, NFA items are prohibited, in Red states, they are typically allowed. The process involves a $200 fee, fingerprinting at a local Law Enforcement office, sign off by your local high-ranking Law Enforcement Official, and 6 to 18 months of waiting while the Bureau of ATF (and really big fires) processes the paperwork and does a stringent background check.
In many areas that an NFA item is otherwise legal, the local high-ranking Law Enforcement Official may simply refuse to sign your paperwork, meaning you may not apply for the item. To subvert this, creating a Trust or Gun Trust has become very popular. As the Trust is not a person, the process was made simpler by eliminating finger printing and the local Law Enforcement sign off.
For obvious reasons the ATF did not like this, so they have been considering changes (ATF 41F). That change was finalized with this Executive order. The general change is, the complete elimination of the Law Enforcement sign off for individual applicants, and that the Trust creator and anyone in the Trust intending to use the NFA item must submit fingerprints, photo ID, etc. so that a background check can be implemented. Thus making NFA items accessible in many more areas (without a trust), while not restricting them in any new areas. Thusly it can be viewed as a win for Pro-Gun persons.
This is all a general summation, please research further if you would like precise details.
https://www.atf.gov/qa-category/national-firearms-act-nfahttp://www.thefirearmblog.com/blog/2014/11/26/setting-nfa-gun-trust/http://www.thetruthaboutguns.com/2016/01/foghorn/breaking-atf-issues-final-ruling-on-nfa-trusts-requires-fingerprints-but-eliminates-cleo-sign-off/Edit: the most common items are silencers, and short barreled rifles, there is active legislation that will most likely not pass, but would eliminate silencers from the NFA