Why not just use the Entity system for '$arg$' and '$opt$' help holders?

Gallery
Tutorial
[TECHNICAL SLIDE TRAIL] The Webel libraries for Wolfram Mathematica: With SysMLv1 models.
Section
SECTION: The Webel '$opt$' and '$arg$' help holder conventions for options and arguments in the Wolfram Language
Mathematica keywords
Entity
Webel Mathematica keywords
help holder
'$arg$'
'$opt$'
Keywords
Click on the image to view it full size
Up next
Association vs Class as SysML CASE: Webel $arg$ and $opt$ help
Notes
[NAMING, PATTERN, POLICY]{STRICT} Webel: Mathematica: CONVENTION: Argument help holders use a String variable with the prefix '$arg$', a related '$info$arg$' String, a 'def$arg$' default value expression and/or 'req$arg$', and optional '$warn$arg$', '$tip$arg$, '$lab$arg$', 'type$arg$'..
[NAMING, PATTERN, POLICY]{STRICT} Webel: Mathematica: CONVENTION: Option help holders use a String variable with the prefix '$opt$', a related '$info$opt$' String, a 'def$opt$' default value expression, and optional '$warn$opt$', '$tip$opt$', '$lab$opt$', and 'type$opt$' indicator ...
Snippets (quotes/extracts)
Visit also
The Webel SysML4Mathematica recipe for modelling Wolfram Language code in Systems Modeling Language (SysML) for Model-Based Systems Engineering
Visit also (backlinks)
Related slides (includes other tutorials)
The Webel '$opt$', 'rule$opt$', '$arg$', 'rule$arg$' and supporting '$k$' conventions for "help holders"
Webel ‘$arg$’, ‘def$arg$’, and ‘rule$arg$’ convention
Webel '$arg$' and '$opt$' support via the Doc` package
Make a Webel help Rule for a required ‘$arg$’ argument + conventions
Related slides (backlinks, includes other tutorials)
HelpO`: Part of the help registry for the Webel MAll universal MTools class and some methods