Function construct_heading 

pub fn construct_heading(def: &ComponentDef<'_>, interner: &Interner) -> String

How an LGX construct is named in a refusal: by the header its author wrote.

A page’s component is interned under a lowered name (__page__about) that appears nowhere in the file, so a page is named by its ## Page header, an error page by its status, and a component by its declaration — called by both the tree-walker and the VM compiler so the wording cannot diverge between them.