Editing messages using the AJAX tool - using a klick point in the lower left edge.
When selecting a piece of text in the edit field first, then klicking on one of the labels in the lower left edge of the edit field, such as [$1] or [GENDER:$2], the selected text is not replaced. When typing on the keyboard, it is. That is somewhat counter-intuitive.
Reported as phab:T114101