latex customized enumerate list

Latex allows the creation of enumerated (ordered) lists up to four deep. The numbering styles for each depth can be styled to suit your needs using the \renewcommand{label}{style} command, where label is the list depth being styled and style is how you want that number to be shown.

label may be any of the following:

\labelenumi: first level
\labelenumii: second level
\labelenumiii: third level
\labelenumiv: fourth level

style may be any combination of characters and numbers. The item number for each list may be printed using by using any of the following (from first depth to fourth depth):

enumi
enumii
enumiii
enumiv

These numbers may be styled with the following macros:

\alph{number}: lowercase letters
\Alph{number}: uppercase letters
\arabic{number}: numbers
\roman{number}: lowercase roman numerals
\Roman{number}: uppercase roman numerals

That’s a lot to take in, so let’s look at an example. If we want to generate a list which is numbered a style like this:

1. First level
1. a) Second level
1. a) i: Third level

Then we would style the list like so:

\renewcommand{\labelenumi}{\arabic{enumi}. }
\renewcommand{\labelenumii}{\labelenumi\alph{enumii}) }
\renewcommand{\labelenumiii}{\labelenumii\roman{enumiii}: }

This would be added to the top of the document, before \begin{document}.

\begin{enumerate}
\renewcommand{\theenumi}{P\arabic{enumi}}
\renewcommand{\labelenumi}{(\theenumi)}
\renewcommand{\theenumii}{(\alph{enumii})}
\renewcommand{\labelenumii}{\theenumii}
\end{enumerate}