\documentclass[10pt,a4paper]{article}

% Packages
\usepackage{fancyhdr}           % For header and footer
\usepackage{multicol}           % Allows multicols in tables
\usepackage{tabularx}           % Intelligent column widths
\usepackage{tabulary}           % Used in header and footer
\usepackage{hhline}             % Border under tables
\usepackage{graphicx}           % For images
\usepackage{xcolor}             % For hex colours
%\usepackage[utf8x]{inputenc}    % For unicode character support
\usepackage[T1]{fontenc}        % Without this we get weird character replacements
\usepackage{colortbl}           % For coloured tables
\usepackage{setspace}           % For line height
\usepackage{lastpage}           % Needed for total page number
\usepackage{seqsplit}           % Splits long words.
%\usepackage{opensans}          % Can't make this work so far. Shame. Would be lovely.
\usepackage[normalem]{ulem}     % For underlining links
% Most of the following are not required for the majority
% of cheat sheets but are needed for some symbol support.
\usepackage{amsmath}            % Symbols
\usepackage{MnSymbol}           % Symbols
\usepackage{wasysym}            % Symbols
%\usepackage[english,german,french,spanish,italian]{babel}              % Languages

% Document Info
\author{Gruenauge}
\pdfinfo{
  /Title (dtds-for-xml.pdf)
  /Creator (Cheatography)
  /Author (Gruenauge)
  /Subject (DTDs for XML Cheat Sheet)
}

% Lengths and widths
\addtolength{\textwidth}{6cm}
\addtolength{\textheight}{-1cm}
\addtolength{\hoffset}{-3cm}
\addtolength{\voffset}{-2cm}
\setlength{\tabcolsep}{0.2cm} % Space between columns
\setlength{\headsep}{-12pt} % Reduce space between header and content
\setlength{\headheight}{85pt} % If less, LaTeX automatically increases it
\renewcommand{\footrulewidth}{0pt} % Remove footer line
\renewcommand{\headrulewidth}{0pt} % Remove header line
\renewcommand{\seqinsert}{\ifmmode\allowbreak\else\-\fi} % Hyphens in seqsplit
% This two commands together give roughly
% the right line height in the tables
\renewcommand{\arraystretch}{1.3}
\onehalfspacing

% Commands
\newcommand{\SetRowColor}[1]{\noalign{\gdef\RowColorName{#1}}\rowcolor{\RowColorName}} % Shortcut for row colour
\newcommand{\mymulticolumn}[3]{\multicolumn{#1}{>{\columncolor{\RowColorName}}#2}{#3}} % For coloured multi-cols
\newcolumntype{x}[1]{>{\raggedright}p{#1}} % New column types for ragged-right paragraph columns
\newcommand{\tn}{\tabularnewline} % Required as custom column type in use

% Font and Colours
\definecolor{HeadBackground}{HTML}{333333}
\definecolor{FootBackground}{HTML}{666666}
\definecolor{TextColor}{HTML}{333333}
\definecolor{DarkBackground}{HTML}{A3A3A3}
\definecolor{LightBackground}{HTML}{F3F3F3}
\renewcommand{\familydefault}{\sfdefault}
\color{TextColor}

% Header and Footer
\pagestyle{fancy}
\fancyhead{} % Set header to blank
\fancyfoot{} % Set footer to blank
\fancyhead[L]{
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{C}
    \SetRowColor{DarkBackground}
    \vspace{-7pt}
    {\parbox{\dimexpr\textwidth-2\fboxsep\relax}{\noindent
        \hspace*{-6pt}\includegraphics[width=5.8cm]{/web/www.cheatography.com/public/images/cheatography_logo.pdf}}
    }
\end{tabulary}
\columnbreak
\begin{tabulary}{11cm}{L}
    \vspace{-2pt}\large{\bf{\textcolor{DarkBackground}{\textrm{DTDs for XML Cheat Sheet}}}} \\
    \normalsize{by \textcolor{DarkBackground}{Gruenauge} via \textcolor{DarkBackground}{\uline{cheatography.com/207914/cs/44447/}}}
\end{tabulary}
\end{multicols}}

\fancyfoot[L]{ \footnotesize
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{LL}
  \SetRowColor{FootBackground}
  \mymulticolumn{2}{p{5.377cm}}{\bf\textcolor{white}{Cheatographer}}  \\
  \vspace{-2pt}Gruenauge \\
  \uline{cheatography.com/gruenauge} \\
  \end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Cheat Sheet}}  \\
   \vspace{-2pt}Not Yet Published.\\
   Updated 25th September, 2024.\\
   Page {\thepage} of \pageref{LastPage}.
\end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Sponsor}}  \\
  \SetRowColor{white}
  \vspace{-5pt}
  %\includegraphics[width=48px,height=48px]{dave.jpeg}
  Measure your website readability!\\
  www.readability-score.com
\end{tabulary}
\end{multicols}}




\begin{document}
\raggedright
\raggedcolumns

% Set font size to small. Switch to any value
% from this page to resize cheat sheet text:
% www.emerson.emory.edu/services/latex/latex_169.html
\footnotesize % Small font.

\begin{multicols*}{2}

\begin{tabularx}{8.4cm}{x{4 cm} x{4 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{8.4cm}}{\bf\textcolor{white}{What is XML?}}  \tn
% Row 0
\SetRowColor{LightBackground}
{\bf{XML}} \{\{nl\}\} (eXtensible Markup Language) & A flexible text format used to store and transport data, designed to be both \{\{nl\}\} human-readable and machine-readable \tn 
% Row Count 6 (+ 6)
% Row 1
\SetRowColor{white}
{\bf{Key features}} & \seqsplit{Platform-independent} \tn 
% Row Count 7 (+ 1)
% Row 2
\SetRowColor{LightBackground}
 & Designed for information exchange \tn 
% Row Count 9 (+ 2)
% Row 3
\SetRowColor{white}
 & Hierarchical structure with custom tags \tn 
% Row Count 11 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{1. DTD Declaration}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{{\bf{External DTD file:}} \newline \textless{}!DOCTYPE root\_element SYSTEM "file.dtd"\textgreater{} \newline  \newline {\bf{Internal DTD file:}} \newline \textless{}!DOCTYPE root\_element {[} \newline   \textless{}!-{}- DTD declarations go here -{}-\textgreater{} \newline {]}\textgreater{}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{SYSTEM: Points to an external DTD file.}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Root Element \& Hierarchy}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{Every XML document has one root element that holds the entire structure.} \tn 
% Row Count 2 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{`\textless{}!ELEMENT candy\_store (category\_chocolate, category\_gummy?)\textgreater{}`}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{8.4cm}{p{6.88 cm} p{1.12 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{8.4cm}}{\bf\textcolor{white}{Entities}}  \tn
% Row 0
\SetRowColor{LightBackground}
\& & \& \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\< & \textless{} \tn 
% Row Count 2 (+ 1)
% Row 2
\SetRowColor{LightBackground}
\> & \textgreater{} \tn 
% Row Count 3 (+ 1)
% Row 3
\SetRowColor{white}
\' & ' \tn 
% Row Count 4 (+ 1)
% Row 4
\SetRowColor{LightBackground}
\" & " \tn 
% Row Count 5 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\SetRowColor{LightBackground}
\mymulticolumn{2}{x{8.4cm}}{`\textless{}!ENTITY copy "Copyright SweetWorld 2023"\textgreater{}` \newline  \newline Called in the XML document with `\©`.}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{Parameter Entities}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{Reusable definitions within a DTD.} \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{Allows complex content to be reused in multiple elements.} \tn 
% Row Count 3 (+ 2)
% Row 2
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{`\textless{}!ENTITY \% product "(price, manufacturer?, images?,\{\{nl\}\} description?, nutritional\_info?)"\textgreater{}`} \tn 
% Row Count 5 (+ 2)
% Row 3
\SetRowColor{white}
\mymulticolumn{1}{x{8.4cm}}{`\textless{}!ELEMENT chocolate\_bar \%product;\textgreater{}`} \tn 
% Row Count 6 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{8.4cm}{p{0.8 cm} x{7.2 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{8.4cm}}{\bf\textcolor{white}{Element Occurrence}}  \tn
% Row 0
\SetRowColor{LightBackground}
? & Optional, zero or one occurrence \tn 
% Row Count 1 (+ 1)
% Row 1
\SetRowColor{white}
* & Optional, zero, one, or more occurrences \tn 
% Row Count 3 (+ 2)
% Row 2
\SetRowColor{LightBackground}
+ & At least one occurrence \tn 
% Row Count 4 (+ 1)
% Row 3
\SetRowColor{white}
, & Elements must appear in the given order \tn 
% Row Count 6 (+ 2)
% Row 4
\SetRowColor{LightBackground}
| & Either one element or the other \tn 
% Row Count 7 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\SetRowColor{LightBackground}
\mymulticolumn{2}{x{8.4cm}}{`\textless{}!ELEMENT nutritional\_info (calories?, fat\_content?,\{\{nl\}\} sugar\_content?)\textgreater{}` \newline Calories, fat\_content, and sugar\_content are optional.}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{8.4cm}{x{4 cm} x{4 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{8.4cm}}{\bf\textcolor{white}{What is a DTD?}}  \tn
% Row 0
\SetRowColor{LightBackground}
{\bf{DTD}} \{\{nl\}\} (Document Type \{\{nl\}\} Definition) & Defines the structure and rules for an XML document.\{\{nl\}\} It ensures that the XML follows a specific schema. \tn 
% Row Count 6 (+ 6)
% Row 1
\SetRowColor{white}
{\bf{Key features}} & Elements \tn 
% Row Count 7 (+ 1)
% Row 2
\SetRowColor{LightBackground}
 & Attributes \tn 
% Row Count 8 (+ 1)
% Row 3
\SetRowColor{white}
 & Entities \tn 
% Row Count 9 (+ 1)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{8.4cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{8.4cm}}{\bf\textcolor{white}{2. Element Declarations}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{\textless{}!ELEMENT element\_name (content)\textgreater{} \newline \textless{}!ELEMENT element\_name EMPTY\textgreater{} \newline  \newline Example with sub-elements: \newline \textless{}!ELEMENT candy\_types (chocolate, gummy, hard\_candy)\textgreater{} \newline  \newline Example with text content: \newline \textless{}!ELEMENT description (\#PCDATA)\textgreater{}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{8.4cm}}{{\bf{EMPTY}}: If the element has no content \newline {\bf{PCDATA}}: Parsed Character Data is text that will be parsed by the XML parser. Tags inside are treated as markup and entities will be expanded. \newline {\bf{CDATA}}: (Unparsed) Character data is text which is not parsed further in an XML document. \newline Tags inside are not treated as markup and entities will not be expanded.}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{8.4cm}{x{1.76 cm} x{6.24 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{8.4cm}}{\bf\textcolor{white}{Attributes}}  \tn
% Row 0
\SetRowColor{LightBackground}
\mymulticolumn{2}{x{8.4cm}}{`\textless{}!ATTLIST element\_name attribute\_name type status\textgreater{}`} \tn 
% Row Count 2 (+ 2)
% Row 1
\SetRowColor{white}
\mymulticolumn{2}{x{8.4cm}}{Status:} \tn 
% Row Count 3 (+ 1)
% Row 2
\SetRowColor{LightBackground}
\seqsplit{\#REQUIRED} & must be present \tn 
% Row Count 5 (+ 2)
% Row 3
\SetRowColor{white}
\seqsplit{\#IMPLIED} & optional \tn 
% Row Count 6 (+ 1)
% Row 4
\SetRowColor{LightBackground}
\#FIXED & fixed value \tn 
% Row Count 7 (+ 1)
% Row 5
\SetRowColor{white}
Types: & CDATA (any character string) \tn 
% Row Count 8 (+ 1)
% Row 6
\SetRowColor{LightBackground}
 & Enumerations (predefined values) \tn 
% Row Count 10 (+ 2)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\SetRowColor{LightBackground}
\mymulticolumn{2}{x{8.4cm}}{Example: \newline `\textless{}!ATTLIST candy chocolate\_flavor CDATA \#REQUIRED sugar\_content\{\{nl\}\} CDATA \#REQUIRED\textgreater{}` \newline  \newline Attributes: chocolate\_flavor, sugar\_content \newline Element: candy}  \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}


% That's all folks
\end{multicols*}

\end{document}