Function escape_markup 

pub fn escape_markup(text: &str) -> String

<, > and & as entities, so text written into a marked-up section holds no angle bracket and cannot close that section or open another. The one escaper: the job file’s sections, a resident’s letter and a rebuilt opening all write through it, so what one renderer refuses the others refuse too (crates/city/spec/SpineFiles.lean D21, crates/runtime/spec/Conversation.lean §8-47-2).