The Second Instruction is Continual Placement
Remaining single pointedly upon the object as in the first instruction, Placing the Mind. Using mindfullness and alertness to watch out for movement, when the concentration is extended longer without distraction, this is called Continual Placement.

Excerpt of text written by Khenpo Karten Rinpoche, from the book Precious Teachings, chapter entitled “Nine Instructions for Concentration Meditation,” page 110 in the paper book, and page 118 in the PDF version.