diff --git a/Inst_eddies/get_1_outerm.f90 b/Inst_eddies/get_1_outerm.f90
index 008afc2f1fbdc4e6d256b19cb845427ff3adbc11..0ce7af7886f6260b8aa2ac087ca88057dff9a2ff 100644
--- a/Inst_eddies/get_1_outerm.f90
+++ b/Inst_eddies/get_1_outerm.f90
@@ -65,7 +65,7 @@ contains
     ! number of good contours found and stored, 0 <= n_cont <= n_max_cont - 1
 
     logical, intent(in):: cyclone
-    real, intent(in):: coord_extr(:) ! (2)
+    real, intent(in):: coord_extr(:) ! (2) longitude and latitude, in rad
 
     real, intent(in):: innermost_level_2
     ! ssh level of the innermost contour to consider around the target
@@ -79,7 +79,8 @@ contains
     real, intent(in):: ssh(:, :) ! in m
 
     real, intent(in):: corner(:) ! (2)
-    ! longitude and latitude corresponding to ssh(1,1), in rad
+    ! Longitude and latitude corresponding to ssh(1,1), in rad. A
+    ! priori, this is not the corner of the grid of the NetCDF file.
 
     real, intent(in):: step(:) ! (2)
     ! longitude and latitude steps, in rad
diff --git a/Inst_eddies/good_contour.f90 b/Inst_eddies/good_contour.f90
index 9eb3e0b119660f1fc892c5c95aec4a00cde54725..b0810f88a85de39d38d62762ccf6abfb241a8ebb 100644
--- a/Inst_eddies/good_contour.f90
+++ b/Inst_eddies/good_contour.f90
@@ -13,7 +13,8 @@ contains
     ! procedure returns the first satisfying contour it finds. If such
     ! a contour does not exist, the procedure returns a null
     ! polyline. The order of points in the contour (clockwise or
-    ! counter-clockwise) is not specified.
+    ! counter-clockwise) is not specified. The contour is in
+    ! projection (x, y) coordinates.
 
     ! Libraries:
     use contour_531, only: polyline, find_contours_reg_grid, null_polyline
@@ -26,8 +27,10 @@ contains
     ! zmax.
 
     real, intent(in):: level
-    real, intent(in):: inside_point(:) ! (2)
+    real, intent(in):: inside_point(:) ! (2) (x, y)
+
     real, intent(in), optional:: outside_points(:, :) ! (2, n_out)
+    ! in projection (x, y) coordinates
 
     ! Local:
     type(polyline), allocatable:: contours(:)
diff --git a/Inst_eddies/set_contours.f90 b/Inst_eddies/set_contours.f90
index 6d4527b5409ac76955a2c6d45a2a55c546fb63b9..1d040ee252c6781c2b8cbf919ac4b18206b56017 100644
--- a/Inst_eddies/set_contours.f90
+++ b/Inst_eddies/set_contours.f90
@@ -41,8 +41,10 @@ contains
     real, intent(in), dimension(:, :):: ssh, u, v
     ! sea-surface height, in m, and wind, in m s-1
 
-    real, intent(in):: corner(:) ! (2) longitude and latitude of the
-    ! corner of the grid, in rad
+    real, intent(in):: corner(:) ! (2)
+    ! Longitude and latitude of the corner of the grid, in rad,
+    ! corresponding to ssh(1, 1). A priori, this is not the corner of
+    ! the grid of the NetCDF file.
 
     real, intent(in):: outside_points(:, :) ! (2, :) longitude and
     ! latitude, in rad, of all the significant extrema, except the
diff --git a/Inst_eddies/set_max_speed.f90 b/Inst_eddies/set_max_speed.f90
index 27a763b0f55437700775064d78378f785226019f..6b51edb94cf4adc2829b06dcf2858d9cdddab956 100644
--- a/Inst_eddies/set_max_speed.f90
+++ b/Inst_eddies/set_max_speed.f90
@@ -65,7 +65,9 @@ contains
     ! not exclude other extrema.
 
     real, intent(in):: corner(:) ! (2)
-    ! longitude and latitude of the lower left corner of the grid, in rad
+    ! Longitude and latitude of the lower left corner of the grid,
+    ! corresponding to ssh(1, 1), in rad. A priori, this is not the
+    ! corner of the grid of the NetCDF file.
 
     real, intent(in):: step(:) ! (2) longitude and latitude steps, in rad