Webel IT Australia promotes the amazing Mathematica tool and the powerful Wolfram Language and offers professional Mathematica services for computational computing and data analysis. Our Mathematica
tips, issue tracking, and wishlist is offered here most constructively to help improve the tool and language and support the Mathematica user community.
DISCLAIMER: Wolfram Research does not officially endorse analysis by Webel IT Australia.
In the Webel recipe for modelling Mathematica code in Systems Modeling Language v1 (SysML®) - specifically SysMLv1.x - an '@' prefix in the name of a Block indicates a data structure (such an Association or List) that is not encapsulated in Mathematica code as an MTools class.
Where such a Block represents an Association '<||>' or List '{}' it may extend one of the corresponding representing Blocks:
Typically a Block prefixed with '@' represents an "analysis" block that is a candidate for upgrading to an MTools class.