diff --git a/Categories.mediawiki b/Categories.mediawiki
index f216e8a..04f7602 100644
--- a/Categories.mediawiki
+++ b/Categories.mediawiki
@@ -9,4 +9,4 @@ The following categories contain pages or media.
 * [[Category Packet 474]] (1 members)
 * [[Category Packet {{{revision}}}]] (1 members)
 * [[Category RS2]] (12 members)
-* [[Category RSC]] (6 members)
+* [[Category RSC]] (7 members)
diff --git a/Category-RSC.mediawiki b/Category-RSC.mediawiki
index 0864d2d..63c29a0 100644
--- a/Category-RSC.mediawiki
+++ b/Category-RSC.mediawiki
@@ -1,10 +1,11 @@
 This page will display any information regarding RSC.
 <!-- DO NOT EDIT BELOW THIS LINE, OR CHANGE THIS COMMENT, CODE AUTOMATICALLY GENERATED BY category.sh -->
 == '''Pages in category "RSC"''' ==
-The following 6 pages are in this category.
+The following 7 pages are in this category.
 * [[135 Protocol]]
 * [[202 Protocol]]
 * [[204 Items]]
 * [[204 NPCs]]
 * [[204 Objects]]
 * [[204 Protocol]]
+* [[OB3]]
diff --git a/OB3.mediawiki b/OB3.mediawiki
new file mode 100644
index 0000000..a0c99c3
--- /dev/null
+++ b/OB3.mediawiki
@@ -0,0 +1,37 @@
+[[Category RSC]]
+
+Work in progress.
+
+This page refers to .ob3, a custom format for 3D models created by Jagex. It is used by the RuneScape Classic engine.
+
+ [Unsigned Short] vertex_count
+ [Unsigned Short] face_count
+ 
+ for (int i = 0; i < vertex_count; i++)
+   [Signed Short] vert_x
+ for (int i = 0; i < vertex_count; i++)
+   [Signed Short] vert_z
+ for (int i = 0; i < vertex_count; i++)
+   [Signed Short] vert_y
+ 
+ for (int i = 0; i < face_count; i++)
+   [Unsigned Byte] face_vert_count
+ for (int i = 0; i < face_count; i++)
+   [Signed Short] face_back
+ for (int i = 0; i < face_count; i++)
+   [Signed Short] face_front
+ for (int i = 0; i < face_count; i++)
+   [Unsigned Byte] Unknown boolean, something to do with shading.
+ 
+ for (int i = 0; i < face_count; i++) {
+   for (int j = 0; j < face_vert_count[i]; j++) {
+     if (vertex_count < 256)
+       [Unsigned Byte] Unknown
+     else
+       [Unsigned Short] Unknown
+   }
+ }
+
+== '''Face sides''' ==
+
+A '''negative''' face_back or face_front value indicates a '''solid colour''', whereas a '''positive''' value indicates a '''texture'''.
\ No newline at end of file