diff --git a/km3net-dataformat-specifications.tex b/km3net-dataformat-specifications.tex
index 19777de7f9ad239244ab57f6b64d70c00743b3df..92cd1c018d2610420380127290bb610b39f692a5 100644
--- a/km3net-dataformat-specifications.tex
+++ b/km3net-dataformat-specifications.tex
@@ -2,7 +2,13 @@
 
 \usepackage{graphicx}
 \usepackage{color}
-\usepackage{xurl}
+\usepackage[hidelinks]{hyperref}
+\hypersetup{
+  colorlinks   = true,    % Colours links instead of ugly boxes
+  urlcolor     = blue,    % Colour for external hyperlinks
+  linkcolor    = blue,    % Colour of internal links
+  citecolor    = red      % Colour of citations
+}
 \usepackage{alertmessage}
 \usepackage{listings}
 % \usepackage{forest}
@@ -150,7 +156,7 @@ dom_id line_id floor_id npmts\n
   \datafield[string]{format_version}{The version of the data format with the following format: (v|V)[1-9][0-9]+}
   \datafield[float with 0.1 precision, min: 0.0]{UTC_validity_from}{The begin of the valid time range for the detector description in seconds.}
   \datafield[float with 0.1 precision, max: 999999999999.9]{UTC_validity_to}{The end of the valid time range for the detector description in seconds.}
-  \datafield[string]{UTM_ref_grid}{The reference ellipsoid of the UTM grid of the detector, e.g. "UTM WGS84 33N"}
+  \datafield[string]{UTM_ref_grid}{The reference grid, composed of the string \verb|UTM|, the reference ellipsoid and the UTM grid of the detector, e.g. "UTM WGS84 33N" for the ARCA site in Italy.}
   \datafield[int]{UTM_ref_easting, UTM_ref_northing, UTM_ref_z}{Easting, Northing and z-position of the reference point in the UTM grid. See Section~\ref{section:utm_grid} for more information.}
   \datafield[unsigned int]{ndoms}{Number of optical modules, can be 0, which automatically means the ``end of the file''.}
   \datafield[int]{dom_id}{The unique optical module ID. For real detectors, the number is part of the product number and is usually the last 9 digits of the CLBs MAC address.}
@@ -168,12 +174,13 @@ dom_id line_id floor_id npmts\n
 
 \subsubsection{UTM Grid}
 \label{section:utm_grid}
+
 The KM3NeT coordinate system is proposed in \verb|KM3NeT_SOFT_WD_2016_002|, the reference
 point for the ARCA site is defined within the building block one with:
 
 \begin{itemize}
   \item UTM reference ellipsoid: WGS84
-  \item UTM grid zone: 33N (where N is for North\footnote{A note of caution: The method used here simply adds N or S following the zone number to indicate Northern or Southern hemisphere. See \url{https://en.wikipedia.org/wiki/Universal_Transverse_Mercator_coordinate_system#Notation} for a general discussion on the grid zone notation})
+  \item UTM grid zone: 33N (where N is for North\footnote{A note of caution: The method used here simply adds N or S following the zone number to indicate Northern or Southern hemisphere. See \url{https://en.wikipedia.org/wiki/Universal_Transverse_Mercator_coordinate_system\#Notation} for a general discussion on the grid zone notation})
   \item The elevation (\verb|UTM_ref_z|) above is the orthometric height calculated relative to the mean sea surface (MSS) as defined by \verb|DTU132|. The see \verb|WGS84| geoid height can be deduced by adding the \verb|EGM96| Geoid height which is \SI{30.9(0.1)}{\meter} at the reference point, as provided by the \verb|NGA EGM96 Geoid Calculator|; the orthometric height of the seafloor at that point is \SI{-3454(1)}{\meter} and the mean for the ARCA building block is \SI{-3452}{\meter}.
 \end{itemize}
 
@@ -223,7 +230,7 @@ for every PMT and comment lines at the beginning of the file to store meta data.
   \datafield[string]{format_version}{The version of the data format with the following format: (v|V)[1-9][0-9]+}
   \datafield[float with 0.1 precision, min: 0.0]{UTC_validity_from}{The begin of the valid time range for the detector description in seconds.}
   \datafield[float with 0.1 precision, max: 999999999999.9]{UTC_validity_to}{The end of the valid time range for the detector description in seconds.}
-  \datafield[string]{UTM_ref_grid}{The reference ellipsoid of the UTM grid of the detector, e.g. "UTM WGS84 33N"}
+  \datafield[string]{UTM_ref_grid}{The reference grid, composed of the string \verb|UTM|, the reference ellipsoid and the UTM grid of the detector, e.g. "UTM WGS84 33N" for the ARCA site in Italy.}
   \datafield[int]{UTM_ref_easting, UTM_ref_northing, UTM_ref_z}{Easting, Northing and z-position of the reference point in the UTM grid. See Section~\ref{section:utm_grid} for more information.}
   \datafield[unsigned int]{ndoms}{Number of optical modules, can be 0, which automatically means the ``end of the file''.}
   \datafield[int]{dom_id}{The unique optical module ID. For real detectors, the number is part of the product number and is usually the last 9 digits of the CLBs MAC address.}
@@ -285,7 +292,7 @@ for defining non-optical modules (like base modules).
   \datafield[string]{format_version}{The version of the data format with the following format: (v|V)[1-9][0-9]+}
   \datafield[float with 0.1 precision, min: 0.0]{UTC_validity_from}{The begin of the valid time range for the detector description in seconds.}
   \datafield[float with 0.1 precision, max: 999999999999.9]{UTC_validity_to}{The end of the valid time range for the detector description in seconds.}
-  \datafield[string]{UTM_ref_grid}{The reference ellipsoid of the UTM grid of the detector, e.g. "UTM WGS84 33N"}
+  \datafield[string]{UTM_ref_grid}{The reference grid, composed of the string \verb|UTM|, the reference ellipsoid and the UTM grid of the detector, e.g. "UTM WGS84 33N" for the ARCA site in Italy.}
   \datafield[int]{UTM_ref_easting, UTM_ref_northing, UTM_ref_z}{Easting, Northing and z-position of the reference point in the UTM grid. See Section~\ref{section:utm_grid} for more information.}
   \datafield[unsigned int]{nmodules}{Number of optical modules, can be 0, which automatically means the ``end of the file''.}
   \datafield[int]{module_id}{The unique optical module ID. For real detectors, the number is part of the product number and is usually the last 9 digits of the CLBs MAC address.}
@@ -351,7 +358,7 @@ The main additions in the fifth version of the DETX format is the COMPONENTESTAT
   \datafield[string]{format_version}{The version of the data format with the following format: (v|V)[1-9][0-9]+}
   \datafield[float with 0.1 precision, min: 0.0]{UTC_validity_from}{The begin of the valid time range for the detector description in seconds.}
   \datafield[float with 0.1 precision, max: 999999999999.9]{UTC_validity_to}{The end of the valid time range for the detector description in seconds.}
-  \datafield[string]{UTM_ref_grid}{The reference ellipsoid of the UTM grid of the detector, e.g. "UTM WGS84 33N".}
+  \datafield[string]{UTM_ref_grid}{The reference grid, composed of the string \verb|UTM|, the reference ellipsoid and the UTM grid of the detector, e.g. "UTM WGS84 33N" for the ARCA site in Italy.}
   \datafield[int]{UTM_ref_easting, UTM_ref_northing, UTM_ref_z}{Easting, Northing and z-position of the reference point in the UTM grid. See Section~\ref{section:utm_grid} for more information.}
   \datafield[unsigned int]{nmodules}{Number of optical modules, can be 0, which automatically means the ``end of the file''.}
   \datafield[int]{module_id}{The unique module ID. For real detectors, the number is part of the product number and is usually the last 9 digits of the CLBs MAC address.}