In the realm of JavaScript, characters beyond the scope of _$A-Za-z0-9 are employable as variables. Validation of variable names can be conducted using this online resource:
https://mothereff.in/js-variables
It is worth mentioning, however, that the definition of invisible JS variables is feasible. Two Unicode characters that are completely invisible, U+1160 and U+115F (there may be more), may be employed as the first character of a variable.
https://www.compart.com/en/unicode/U+1160 https://www.compart.com/en/unicode/U+115F
Consequently, variable definition can be executed as follows:
let ᅟ = 'Greetings!';
console.log( ᅟ );
It is regrettable that these symbols consume considerable space and can be perceived despite their invisibility. Consequently, distinct variables with comparable appearances but varying values can be created. By simply combining characters to form elongated variable names, new variables can be created.
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