diff --git a/Set_movable_separability_2/doc/Set_movable_separability_2/Set_movable_separability_2.txt b/Set_movable_separability_2/doc/Set_movable_separability_2/Set_movable_separability_2.txt
index d996c8b33a0..85dfd4fa25a 100644
--- a/Set_movable_separability_2/doc/Set_movable_separability_2/Set_movable_separability_2.txt
+++ b/Set_movable_separability_2/doc/Set_movable_separability_2/Set_movable_separability_2.txt
@@ -7,7 +7,7 @@ namespace CGAL {
 \cgalAutoToc
 \authors Shahar Shamai and Efi Fogel
 
-\section sms_sec_intro Introduction
+\section sms_2_sec_intro Introduction
 
 <em>Movable Separability of Sets</em> \cgalCite{t-mss-85} is a class
 of problems that deal with moving sets of objects, such as polygons in
@@ -37,12 +37,12 @@ problems related to 2D castings. In particular, each of these
 solutions handles a single moving polygon and a single stationary
 polygon, and considers a single translation of the moving polygon.
 
-\section sms_sec_casting Casting
+\section sms_2_sec_casting Casting
 
 Casting is a manufacturing process where liquid material is poured
 into a cavity inside a mold, which has the shape of a desired
-product (The mold can take any shape and form as long as it has a
-cavity of the desired shape). After the material solidifies, the
+product. (The mold can take any shape and form as long as it has a
+cavity of the desired shape.) After the material solidifies, the
 product is pulled out of the mold. Typically a mold is used to
 manufacture numerous copies of a product. The challenge is designing a
 proper mold, such that the solidified product can be separated from
@@ -54,7 +54,7 @@ that, given a simple closed polygon \f$P\f$, determines whether a
 cavity (of a mold in the plane) that has the shape of \f$P\f$ can be
 used so that the polygon \f$P\f$ could be pulled out of the mold
 without colliding into the mold (but possibly sliding along the mold
-surface); see \cgalFigureRef{sms_2_fig_polygons} for an
+boundary); see \cgalFigureRef{sms_2_fig_polygons} for an
 illustration. In reality, the mold of a <em>castable</em> polygon must
 be rotated before the polygon is casted, such that one edge becomes
 parallel to the \f$x\f$-axis and is located above all other edges;