diff --git a/documentation/doxygen/Doxyfile b/documentation/doxygen/Doxyfile
index bff77b6b62f78..859cec0152998 100644
--- a/documentation/doxygen/Doxyfile
+++ b/documentation/doxygen/Doxyfile
@@ -269,7 +269,10 @@ TAB_SIZE = 3
# commands \{ and \} for these it is advised to use the version @{ and @} or use
# a double escape (\\{ and \\})
-ALIASES =
+
+ALIASES += legacy{2}="\htmlonly
Legacy Code
The \1 \2 is legacy software: there will be no bug fixes nor new developments. It can be used as it is, but it's not recommended to use it in new code.\endhtmlonly"
+
+
# Set the OPTIMIZE_OUTPUT_FOR_C tag to YES if your project consists of C sources
# only. Doxygen will then generate output that is more tailored for C. For
diff --git a/documentation/doxygen/ROOT.css b/documentation/doxygen/ROOT.css
index 492a38726517c..7f1e461b1356c 100644
--- a/documentation/doxygen/ROOT.css
+++ b/documentation/doxygen/ROOT.css
@@ -23,3 +23,9 @@ div.contents {
background-color: #f9fafc;
padding: 15px;
}
+
+.legacybox {
+ border: 3px solid #879ecb;
+ background-color: #fdf06b;
+ padding: 15px;
+}
diff --git a/hist/spectrum/doc/index.md b/hist/spectrum/doc/index.md
index 7ee7db349e77d..e51d40321557b 100644
--- a/hist/spectrum/doc/index.md
+++ b/hist/spectrum/doc/index.md
@@ -1,6 +1,8 @@
\defgroup Spectrum Advanced spectra processing classes.
\ingroup Hist
+\legacy{Spectrum,package}
+
\authors
Miroslav Morhac
Institute of Physics
diff --git a/hist/spectrum/src/TSpectrum.cxx b/hist/spectrum/src/TSpectrum.cxx
index 3d4915d0dfad0..5aade1a7993b7 100644
--- a/hist/spectrum/src/TSpectrum.cxx
+++ b/hist/spectrum/src/TSpectrum.cxx
@@ -14,6 +14,8 @@
\brief Advanced Spectra Processing
\author Miroslav Morhac
+ \legacy{TSpectrum,class}
+
This class contains advanced spectra processing functions for:
- One-dimensional background estimation
diff --git a/hist/spectrum/src/TSpectrum2.cxx b/hist/spectrum/src/TSpectrum2.cxx
index 9520b17867434..573f7b8302449 100644
--- a/hist/spectrum/src/TSpectrum2.cxx
+++ b/hist/spectrum/src/TSpectrum2.cxx
@@ -6,6 +6,8 @@
\brief Advanced 2-dimensional spectra processing
\author Miroslav Morhac
+ \legacy{TSpectrum2,class}
+
This class contains advanced spectra processing functions.
- One-dimensional background estimation functions
diff --git a/hist/spectrum/src/TSpectrum2Fit.cxx b/hist/spectrum/src/TSpectrum2Fit.cxx
index f25030007ffce..d3bb11ff60b54 100644
--- a/hist/spectrum/src/TSpectrum2Fit.cxx
+++ b/hist/spectrum/src/TSpectrum2Fit.cxx
@@ -6,6 +6,8 @@
\brief Advanced 2-dimensional spectra fitting functions
\author Miroslav Morhac
+ \legacy{TSpectrum2Fit,class}
+
Class for fitting 2D spectra using AWMI (algorithm without matrix
inversion) and conjugate gradient algorithms for symmetrical
matrices (Stiefel-Hestens method). AWMI method allows to fit
diff --git a/hist/spectrum/src/TSpectrum2Transform.cxx b/hist/spectrum/src/TSpectrum2Transform.cxx
index 529c5c81083bf..74307697e8d8c 100644
--- a/hist/spectrum/src/TSpectrum2Transform.cxx
+++ b/hist/spectrum/src/TSpectrum2Transform.cxx
@@ -6,6 +6,8 @@
\brief Advanced 2-dimensional orthogonal transform functions
\author Miroslav Morhac
+ \legacy{TSpectrum2Transform,class}
+
Class to carry out transforms of 2D spectra, its filtering and
enhancement. It allows to calculate classic Fourier, Cosine, Sin,
Hartley, Walsh, Haar transforms as well as mixed transforms (Fourier-
diff --git a/hist/spectrum/src/TSpectrum3.cxx b/hist/spectrum/src/TSpectrum3.cxx
index ba40a58842ced..d6261bce07a36 100644
--- a/hist/spectrum/src/TSpectrum3.cxx
+++ b/hist/spectrum/src/TSpectrum3.cxx
@@ -6,6 +6,8 @@
\brief Advanced 3-dimensional spectra processing functions
\author Miroslav Morhac
+ \legacy{TSpectrum3,class}
+
This class contains advanced spectra processing functions.
- Three-dimensional background estimation functions
diff --git a/hist/spectrum/src/TSpectrumFit.cxx b/hist/spectrum/src/TSpectrumFit.cxx
index 1053fc200f595..5d88a21b78a22 100644
--- a/hist/spectrum/src/TSpectrumFit.cxx
+++ b/hist/spectrum/src/TSpectrumFit.cxx
@@ -6,6 +6,8 @@
\brief Advanced 1-dimensional spectra fitting functions
\author Miroslav Morhac
+ \legacy{TSpectrumFit,class}
+
Class for fitting 1D spectra using AWMI (algorithm without matrix
inversion) and conjugate gradient algorithms for symmetrical
matrices (Stiefel-Hestens method). AWMI method allows to fit
diff --git a/hist/spectrum/src/TSpectrumTransform.cxx b/hist/spectrum/src/TSpectrumTransform.cxx
index e5f983d440db5..ff9d0b0b5dc1f 100644
--- a/hist/spectrum/src/TSpectrumTransform.cxx
+++ b/hist/spectrum/src/TSpectrumTransform.cxx
@@ -6,6 +6,9 @@
\brief Advanced 1-dimensional orthogonal transform functions
\author Miroslav Morhac
+ \legacy{TSpectrumTransform,class}
+
+
Class to carry out transforms of 1D spectra, its filtering and
enhancement. It allows to calculate classic Fourier, Cosine, Sin,
Hartley, Walsh, Haar transforms as well as mixed transforms (Fourier-
diff --git a/hist/spectrumpainter/src/TSpectrum2Painter.cxx b/hist/spectrumpainter/src/TSpectrum2Painter.cxx
index d10da9313ed87..d09b51c75c591 100644
--- a/hist/spectrumpainter/src/TSpectrum2Painter.cxx
+++ b/hist/spectrumpainter/src/TSpectrum2Painter.cxx
@@ -13,6 +13,8 @@
/** \class TSpectrum2Painter
\ingroup Spectrumpainter
+\legacy{TSpectrum2Painter,class}
+
Two-dimensional graphics function
TSpectrum2Painter is a set of graphical functions developed by Miroslav
diff --git a/math/minuit/src/TFitter.cxx b/math/minuit/src/TFitter.cxx
index 73fb9e4fe63d5..0679a1e2a7093 100644
--- a/math/minuit/src/TFitter.cxx
+++ b/math/minuit/src/TFitter.cxx
@@ -22,6 +22,7 @@
////////////////////////////////////////////////////////////////////////////////
/// \class TFitter
+/// \legacy{TFitter,class}
///
/// The ROOT standard fitter based on TMinuit
///
diff --git a/math/splot/src/TSPlot.cxx b/math/splot/src/TSPlot.cxx
index e87977cf95c19..08a6f1bc08329 100644
--- a/math/splot/src/TSPlot.cxx
+++ b/math/splot/src/TSPlot.cxx
@@ -25,6 +25,8 @@ ClassImp(TSPlot);
/** \class TSPlot
+\legacy{TSPlot,class}
+
A common method used in High Energy Physics to perform measurements is
the maximum Likelihood method, exploiting discriminating variables to
disentangle signal from background. The crucial point for such an