DeclareTriads[a1, ..., an]

a1, ..., an: names

The function DeclareTriads establishes the names a1, ..., an as triad labels. A name may only be declared once as a triad label.

The function DeclareTriads results in permanent changes to the global variable GlobalTriadDeclarations.

Restart;
DeclareTriads[a,b,c];
GlobalTriadDeclarations

$\left\{a\to \left\{\right\},b\to \left\{\right\},c\to \left\{\right\}\right\}$

DeclareObservers, DeclarePoints, DefineTriads