%
\documentclass[english,11pt]{book}
%
\usepackage[fleqn]{amsmath} %
\usepackage{amsthm,amssymb} %
\usepackage{xcolor} %
\usepackage[paperwidth=170mm,paperheight=240mm,bindingoffset=12.5mm,left=12.5mm,right=12.5mm,top=8mm,bottom=8mm,showframe,showcrop]{geometry}
\usepackage[a4,frame,cam,center]{crop} %
\usepackage{libertine} %
\usepackage{hyperref}
\definecolor{DarkRed}{rgb}{0.45,0.06,0.06} %
% Theorem - Theorem - Theorem - Theorem - Theorem - Theorem - Theorem - Theorem - Theorem - Theorem - Theorem %
\newtheoremstyle{stacktheorem}
{4pt} % this does not appear to have any effect
{4pt} % this does not appear to work any effect
{\normalfont} %
{-6pt} %
{\libertineSB} %
{\\[4.2pt]} % can this parameter be set to a #1 integer value so as to be set at the point of call?
{0pt} %
{
{\color{DarkRed}\fontsize{11.15}{12}\selectfont{
\thmname{\hspace{1.2pt}#1}%
\thmnumber{\hspace{2.8pt}#2}}} %
\normalfont\thmnote{ \hspace{1.2pt}- \hspace{1.2pt}#3} }%
\theoremstyle{stacktheorem} %
\newtheorem{stacktheorem}{Stack theorem}
\counterwithin{stacktheorem}{chapter}
\renewcommand{\thestacktheorem}{[\hspace{1.1pt}\arabic{stacktheorem}\hspace{1.2pt}]} % formats the label number
\begin{document}
\pagenumbering{arabic} % 1, 2, ...
\setcounter{page}{0}
\setcounter{chapter}{0}
\chapter*{Chapter One}
\section*{Section One}
\begin{stacktheorem}[can the vertical space between this note]
{and this line be set until the point of call\hspace{1.6pt}?}
\end{stacktheorem}
\end{document}