diff --git a/src/tui/light.go b/src/tui/light.go
index 0ded2917..b84653cb 100644
--- a/src/tui/light.go
+++ b/src/tui/light.go
@@ -413,6 +413,12 @@ func stringIntroducer(b byte) bool {
 func incompleteEscape(buffer []byte) bool {
 	// Only the tail can hold a sequence still arriving. This runs once per byte
 	// read, so scanning all of a large paste would make the read quadratic.
+	//
+	// The limit is that a string sequence with a payload longer than this stops
+	// being seen as unfinished, so one that is also split across reads reaches
+	// the parser incomplete and its payload is typed into the query. Recognizing
+	// it would mean tracking the open sequence across reads instead of
+	// rescanning the tail.
 	tail := buffer
 	if len(tail) > escapeLookback {
 		tail = tail[len(tail)-escapeLookback:]