diff --git a/doomsday/engine/api/dd_share.h b/doomsday/engine/api/dd_share.h
index d415ecb029..e9fea13e96 100644
--- a/doomsday/engine/api/dd_share.h
+++ b/doomsday/engine/api/dd_share.h
@@ -804,6 +804,18 @@ enum {
     NUM_REVERB_DATA
 };
 
+/// SideDef section indices. @ingroup map
+typedef enum sidedefsection_e {
+    SS_MIDDLE,
+    SS_BOTTOM,
+    SS_TOP
+} SideDefSection;
+
+/// Helper macro for converting SideDefSection indices to their associated DMU flag. @ingroup map
+#define DMU_FLAG_FOR_SIDEDEFSECTION(s) (\
+    (s) == SS_MIDDLE? DMU_MIDDLE_OF_SIDEDEF : \
+    (s) == SS_BOTTOM? DMU_BOTTOM_OF_SIDEDEF : DMU_TOP_OF_SIDEDEF)
+
 typedef struct {
     fixed_t origin[2];
     fixed_t direction[2];
diff --git a/doomsday/engine/portable/include/mapdata.hs b/doomsday/engine/portable/include/mapdata.hs
index 2fb3e0f416..6f6f2e113e 100644
--- a/doomsday/engine/portable/include/mapdata.hs
+++ b/doomsday/engine/portable/include/mapdata.hs
@@ -313,13 +313,6 @@ struct Sector
 end
 
 internal
-// Sections of a sidedef
-typedef enum sidedefsection_e {
-    SS_MIDDLE,
-    SS_TOP,
-    SS_BOTTOM
-} sidedefsection_t;
-
 // Helper macros for accessing sidedef top/middle/bottom section data elements.
 #define SW_surface(n)           sections[(n)]
 #define SW_surfaceflags(n)      SW_surface(n).flags
diff --git a/doomsday/engine/portable/include/p_maptypes.h b/doomsday/engine/portable/include/p_maptypes.h
index 1cc715ae28..1a14d240a7 100644
--- a/doomsday/engine/portable/include/p_maptypes.h
+++ b/doomsday/engine/portable/include/p_maptypes.h
@@ -296,13 +296,6 @@ typedef struct sector_s {
     msector_t           buildData;
 } Sector;
 
-// Sidedef sections.
-typedef enum sidedefsection_e {
-    SS_MIDDLE,
-    SS_TOP,
-    SS_BOTTOM
-} sidedefsection_t;
-
 // Helper macros for accessing sidedef top/middle/bottom section data elements.
 #define SW_surface(n)           sections[(n)]
 #define SW_surfaceflags(n)      SW_surface(n).flags
diff --git a/doomsday/engine/portable/include/r_world.h b/doomsday/engine/portable/include/r_world.h
index 324d8bb12c..3f39ca2ad2 100644
--- a/doomsday/engine/portable/include/r_world.h
+++ b/doomsday/engine/portable/include/r_world.h
@@ -87,7 +87,7 @@ void R_MapInitSurfaceLists(void);
 
 void            R_OrderVertices(const LineDef* line, const Sector* sector,
                                 Vertex* verts[2]);
-boolean         R_FindBottomTop(LineDef* lineDef, int side, sidedefsection_t section,
+boolean         R_FindBottomTop(LineDef* lineDef, int side, SideDefSection section,
                                 coord_t matOffsetX, coord_t matOffsetY,
                                 const Plane* ffloor, const Plane* fceil,
                                 const Plane* bfloor, const Plane* bceil,
diff --git a/doomsday/engine/portable/src/dam_file.c b/doomsday/engine/portable/src/dam_file.c
index 8ad0775ba2..cc1c3f923c 100644
--- a/doomsday/engine/portable/src/dam_file.c
+++ b/doomsday/engine/portable/src/dam_file.c
@@ -329,7 +329,7 @@ static void writeSide(GameMap* map, uint idx)
 
     for(i = 0; i < 3; ++i)
     {
-        Surface* suf = &s->sections[3];
+        Surface* suf = &s->sections[i];
 
         writeLong(suf->flags);
         //writeLong(getMaterialDictID(materialDict, suf->material));
@@ -359,7 +359,7 @@ static void readSide(GameMap* map, uint idx)
 
     for(i = 0; i < 3; ++i)
     {
-        Surface* suf = &s->sections[3];
+        Surface* suf = &s->sections[i];
 
         suf->flags = (int) readLong();
         //Surface_SetMaterial(suf, lookupMaterialFromDict(materialDict, readLong()));
diff --git a/doomsday/engine/portable/src/r_world.c b/doomsday/engine/portable/src/r_world.c
index 569c270238..2d4ca174b4 100644
--- a/doomsday/engine/portable/src/r_world.c
+++ b/doomsday/engine/portable/src/r_world.c
@@ -1427,7 +1427,7 @@ boolean R_SectorContainsSkySurfaces(const Sector* sec)
  * Non-animated materials are preferred.
  * Sky materials are ignored.
  */
-static material_t* chooseFixMaterial(SideDef* s, sidedefsection_t section)
+static material_t* chooseFixMaterial(SideDef* s, SideDefSection section)
 {
     material_t* choice1 = NULL, *choice2 = NULL;
 
@@ -1462,9 +1462,9 @@ static material_t* chooseFixMaterial(SideDef* s, sidedefsection_t section)
     return NULL;
 }
 
-static void updateSidedefSection(SideDef* s, sidedefsection_t section)
+static void updateSidedefSection(SideDef* s, SideDefSection section)
 {
-    Surface*            suf;
+    Surface* suf;
 
     if(section == SS_MIDDLE)
         return; // Not applicable.
diff --git a/doomsday/engine/portable/src/rend_decor.c b/doomsday/engine/portable/src/rend_decor.c
index 1e0ac9d379..3a3ddbd2ff 100644
--- a/doomsday/engine/portable/src/rend_decor.c
+++ b/doomsday/engine/portable/src/rend_decor.c
@@ -72,7 +72,7 @@ typedef struct decorsource_s {
 
 // PRIVATE FUNCTION PROTOTYPES ---------------------------------------------
 
-static void updateSideSectionDecorations(SideDef* side, sidedefsection_t section);
+static void updateSideSectionDecorations(SideDef* side, SideDefSection section);
 static void updatePlaneDecorations(Plane* pln);
 
 // EXTERNAL DATA DECLARATIONS ----------------------------------------------
@@ -560,7 +560,7 @@ static void updatePlaneDecorations(Plane* pln)
     updateSurfaceDecorations2(suf, offsetS, offsetT, v1, v2, sec, suf->material? true : false);
 }
 
-static void updateSideSectionDecorations(SideDef* side, sidedefsection_t section)
+static void updateSideSectionDecorations(SideDef* side, SideDefSection section)
 {
     LineDef* line;
     Surface* suf;
diff --git a/doomsday/engine/portable/src/rend_main.c b/doomsday/engine/portable/src/rend_main.c
index c5d630becf..f48374fb5a 100644
--- a/doomsday/engine/portable/src/rend_main.c
+++ b/doomsday/engine/portable/src/rend_main.c
@@ -596,7 +596,7 @@ static void applyWallHeightDivision(walldiv_t* divs, const HEdge* hedge,
 }
 
 static void selectSurfaceColors(const float** topColor,
-    const float** bottomColor, SideDef* side, sidedefsection_t section)
+    const float** bottomColor, SideDef* side, SideDefSection section)
 {
     switch(section)
     {
@@ -1735,7 +1735,7 @@ static void Rend_RenderPlane(BspLeaf* bspLeaf, planetype_t type, coord_t height,
     }
 }
 
-static boolean rendHEdgeSection(HEdge* hedge, BspLeaf* bspLeaf, sidedefsection_t section,
+static boolean rendHEdgeSection(HEdge* hedge, BspLeaf* bspLeaf, SideDefSection section,
     Surface* surface, coord_t const from[2], coord_t const to[2], coord_t bottom, coord_t top,
     float const texOffset[2], Sector* frontsec, boolean softSurface, boolean addDLights,
     boolean addMobjShadows, short sideFlags)
@@ -2009,7 +2009,7 @@ static boolean Rend_RenderHEdge(HEdge* hedge, BspLeaf* bspLeaf)
     return solid;
 }
 
-boolean R_FindBottomTop(LineDef* lineDef, int side, sidedefsection_t section,
+boolean R_FindBottomTop(LineDef* lineDef, int side, SideDefSection section,
     coord_t matOffsetX, coord_t matOffsetY,
     const Plane* ffloor, const Plane* fceil,
     const Plane* bfloor, const Plane* bceil,