\newcommand{\cmd}[1]{\texttt{#1}} % shell command
\newcommand{\code}[1]{\texttt{#1}} % for simple code
\newcommand{\func}[1]{%
-\index{#1@{\tt {#1}}}\texttt{#1}%
-} % library function (or system call)
-\newcommand{\macro}[1]{\texttt{#1}} % macro constant
+\index{#1@{{\tt {#1}} (funzione)}}\texttt{#1}%
+}
+\newcommand{\macro}[1]{%
+\index{#1@{{\tt {#1}} (macro)}}\texttt{#1}%
+}
+\newcommand{\errcode}[1]{%
+\index{#1@{{\tt {#1}} (errore)}}\texttt{#1}%
+}
+\newcommand{\errval}[1]{\texttt{#1}} % value
\newcommand{\var}[1]{\texttt{#1}} % variable
+\newcommand{\val}[1]{\texttt{#1}} % value
+\newcommand{\const}[1]{%
+\index{#1@{{\tt {#1}} (costante)}}\texttt{#1}%
+} % constant name
\newcommand{\file}[1]{\texttt{#1}} % file name
\newcommand{\link}[1]{\texttt{#1}} % html link
\newcommand{\ctyp}[1]{\texttt{#1}} % C standard type
\newcommand{\type}[1]{%
-\index{#1@{\tt {#1}}}\texttt{#1}%
+\index{#1@{{\tt {#1}} (tipo)}}\texttt{#1}%
} % system type
\newcommand{\param}[1]{\texttt{#1}} % function parameter
\newcommand{\acr}[1]{\textsl{#1}} % acrostic (for pid, suid, etc.)