How to hide these yellow nodes?

KET_2019

Hi, when i setting the constraints, there are three yellow nodes turned up suddenly. Can someone tell me what are those yellow nodes and how to hide or delete them? Many thanks!!!

<?xml version="1.0" encoding="UTF-8"?>

llyle_20499

Shift+F2 -> clear all

KET_2019

@Livil Lyle thank you very much!