{close} answers PAD's stand-in for the character }, which is turned back into the brace when the page is written out. In between it is text: no tag can end on it, and a pipe or another tag that receives it sees no syntax.

It is the partner of {open}. A lone closing brace in a template is an orphan for the strict check; {close} writes it on purpose. For whole blocks with braces, use {ignore}.

Not to be confused with the close= option of a data tag, which writes a text once after the last occurrence.