diff --git a/doc/userman/user-changes.tex b/doc/userman/user-changes.tex
index 29846545f20f429b6f22f4a13973b36833ed38d0..96e49b547fa49983f7a3ddcd8e79a0cd10c8af5b 100644
--- a/doc/userman/user-changes.tex
+++ b/doc/userman/user-changes.tex
@@ -9,8 +9,6 @@ release. First we list changes of the last release.
 \begin{itemize}
 \item \textbf{Normalizing the Source Code:} document the possibility of
   undefining builtin macros from the chosen \texttt{-machdep}.
-\item \textbf{Preparing the Sources:} add subsection on standard library about
-  portability considerations.
 \end{itemize}
 
 \section*{27.0 (Cobalt)}
diff --git a/doc/userman/user-sources.tex b/doc/userman/user-sources.tex
index fcda6da07c06a1f52a110e650ec11a1469b82ce2..2acb9ad8ac4854369ae8127e59da1288d1523b95 100644
--- a/doc/userman/user-sources.tex
+++ b/doc/userman/user-sources.tex
@@ -601,36 +601,6 @@ As stated before, if you want to ensure the code analyzed by \FramaC is
 strictly equivalent to the one from the target system, you must either
 proofread the definitions, or provide your own library files.
 
-\subsection*{Portability considerations}
-
-A few POSIX types are specified in an abstract way: {\em not required to be
-  arithmetic types}. This enables them to be defined as e.g. structures.
-Portable code using these types must not inspect them or apply operators
-that are only compatible with arithmetic types (e.g. comparing them with
-\texttt{NULL}). However, such comparisons do exist in the wild, and their
-parsing leads to two issues:
-\begin{itemize}
-\item \FramaC will fail parsing with a generic typing error message;
-\item the user may be unable or unwilling to modify the non-portable code,
-  since they may assume a specific libc implementation that uses an arithmetic
-  type.
-\end{itemize}
-The table below lists a few of such types that currently have special support
-in \FramaC's libc: by adding {\em \#define} macros to the preprocessing
-command-line (e.g. via \texttt{-cpp-extra-args=-D<macro>}), the user can ask
-\FramaC to handle such types as arithmetic.
-
-\begin{table}[!ht]
-  \centering
-  \begin{tabular}{l|l|l}
-    \textbf{Type name} & \textbf{Header} & \textbf{Macro name} \\
-    \midrule
-    \lstinline|pthread_t| & \lstinline|sys/types.h| & \lstinline|__FC_PTHREAD_T_IS_SCALAR| \\
-    \lstinline|fexcept_t| & \lstinline|fenv.h| & \lstinline|__FC_FEXCEPT_T_IS_SCALAR| \\
-  \end{tabular}
-\end{table}
-
-
 \section{Warnings during normalization}\label{sec:warnings-normalize}
 
 \emph{Note: the options below are deprecated, replaced by the more general and