This is a SHACL implementation of the ANSI/ASHRAE/NEMA Standard 201-2016, commonly known as FSGIM (Facility Smart Grid Information Model). It is compatible with TopBraid Composer Maestro, version 6.2. The file fsgim.ttl is a SHACL file using the Turtle format, and contains all of the classes and properties specified in the UML model of the ASHRAE Standard, published in 2016. While attempts have been made to be as consistent as possible with the UML specification, there are a few cases where there are differences, such as the UML "redefines" relation, which is inconsistent with the set theory underlying OWL.
Please note that there are two alternate versions of fsgim.ttl, because there are different modeling styles. The version in the folder "anonymous nodes" uses anonymous nodes (b-nodes) when modeling properties of classes. In this version, a given class and all its properties are contained in a single turtle statement. Alternatively, the version in the folder "explicit-nodes" uses a naming convention to give explicit names to each property of a class. In this second version, a given class is more compactly described, but each property (and its constraints) are described separately.
Either version is functionally equivalent, but some prefer reading the source code in one version or the other. You should load only one of them in your environment.