diff --git a/contents/user-input.tex b/contents/user-input.tex
index 0b03896a6ca37f6acbbcd2c56c530b59d27f4c77..c6b0faa8bcc40ed9e3ef92d782f1c70a3c6c7cfe 100644
--- a/contents/user-input.tex
+++ b/contents/user-input.tex
@@ -10,5 +10,34 @@
 % International License (<https://creativecommons.org/licenses/by-sa/4.0/>)
 % ------------------------------------------------------------------------------
 
-\chapter{Input file}
+\chapter{Configuration file}
 \label{chap:user:input}
+
+A simulation with \rotare is controlled by a single configuration file. This
+file contains all data related to the behavior of the software, the models and
+solvers to use, the flow, the operating points to analyze and the rotor
+geometry itself. These five types of input are collected inside five different
+structures for easier handling in the code.
+
+This input file should be a \matlab script (not a function). Examples of
+configuration are given in src/config. In order to always have a fully-defined,
+working configuration available, it is suggested to just copy the template and
+edit your copy instead of directly working in the template.
+
+
+\section{Input variables}
+
+
+\section{Configuration validation}
+
+Before initiating a simulation, the user input file is passed through a
+validation function. This function checks if all inputs are properly defined and
+formatted before starting the simulation. It also fixes small typos in the
+string parameters whenever possible to ensure proper behavior of the software.
+
+If the validation of a parameter fails, a comprehensive error message will be
+returned. This should help the user to fix their issues easily.
+
+The validation function will also return preliminary warnings whenever some
+parameters may lead to potential issues. These warnings can easily be turned
+off.
diff --git a/doc-setup.tex b/doc-setup.tex
index 08fcb6092dd5c65339a10906c1939caacec0634b..22a7d6a5cc34f8287b4ce5f6b9996a436d0c8d2b 100644
--- a/doc-setup.tex
+++ b/doc-setup.tex
@@ -82,3 +82,4 @@
 % ==============================================================================
 
 \usepackage{scrhack} % So other packages play nice with KOMA-Scripts
+\usepackage{definitions} % Custom definitions (see style/definitions.sty)
diff --git a/style/definitions.sty b/style/definitions.sty
new file mode 100644
index 0000000000000000000000000000000000000000..7193ed6e21632ccc6f0ed8c091722169ece15041
--- /dev/null
+++ b/style/definitions.sty
@@ -0,0 +1,49 @@
+% -----------------------------------------------------------------------------
+% List of definitions to ensure coherence in the notation between the abstract,
+% the paper and the presentation.
+%
+% Author: Thomas Lambert <t.lambert@uliege.be>
+% ULiege - Aeroelasticity and Experimental Aerodynamics
+% MIT License
+% https://gitlab.uliege.be/thlamb/bemt
+% ------------------------------------------------------------------------------
+
+\RequirePackage{xspace}
+\RequirePackage{fontawesome5}
+\RequirePackage{xcolor}
+
+
+% --- Better colors ------------------------------------------------------------
+
+\definecolor{myRed}{RGB}{230,45,49}
+\definecolor{myGreen}{RGB}{40,155,56}
+\definecolor{myOrange}{RGB}{248,170,0}
+
+% --- Shortcuts ----------------------------------------------------------------
+\newcommand{\todo}[1]{\textcolor{red}{TODO: #1} \noindent}
+
+\newcommand{\latin}[1]{\textit{#1}}
+\newcommand{\ie}{\latin{i.e.}}
+\newcommand{\eg}{\latin{e.g.}}
+\newcommand{\etal}{\latin{et~al.}~}
+
+\newcommand{\coderepoURL}{https://gitlab.uliege.be/thlamb/rotare}
+\newcommand{\codedocURL}{https://gitlab.uliege.be/thlamb/rotare-doc}
+
+\newcommand{\gV}{\textcolor{myGreen}{\faCheck}}
+\newcommand{\rX}{\textcolor{myRed}{\faTimes}}
+\newcommand{\yQ}{\textcolor{myOrange}{\faQuestion}}
+\newcommand{\oV}{\textcolor{myOrange}{\faCheck}}
+
+% --- Code & software names, ---------------------------------------------------
+\newcommand\rotare{\textsc{Rotare}\xspace}
+\newcommand\matlab{\textsc{Matlab}\xspace}
+\newcommand\QBlade{\textsc{QBlade}\xspace}
+\newcommand\JBlade{\textsc{JBlade}\xspace}
+\newcommand\pyBEMT{\textsc{pyBEMT}\xspace}
+\newcommand\AeroDyn{\textsc{AeroDyn}\xspace}
+
+% --- Velocities ---------------------------------------------------------------
+
+% --- Angles -------------------------------------------------------------------
+