The Mesh page of the Object Settings dialog:

Pivot

The average of the transform's Rotate and Scale pivot is taken into consideration when exporting meshes. For consistency, you should always set the same value for both pivots.

Mesh Settings

• Mesh Name - The name of the exported mesh. If not specified, the object name is used.
• Primitive Type - The type of primitives used to render the mesh.
• Vertex Buffer Usage - The behavior of the vertex buffer.
• Vertex Buffer Usage - Use Shadow - Indicates whether a shadow buffer should be maintained for the vertex buffer.
• Index Buffer Usage - The behavior of the index buffer.
• Index Buffer Usage - Use Shadow - Indicates whether a shadow buffer should be maintained for the index buffer.
• Export Vertex Colors - Indicates whether vertex colors should be exported.
• Generate Edge Lists - Indicates whether edge lists are generated for meshes.
• Remove Duplicate Vertices - Indicates whether duplicate vertices should be removed. Removing duplicate vertices slows down the export process.
• Animate Bounding Volumes - Indicates whether mesh bounding volumes should be calculated using an animated version of the mesh. Enabling this setting slows down the export process.
• Make Bounding Box Cub - Indicates whether the mesh bounding box should be exported as a cube, with each side taken to be the largest of the non-cube version of the bounding box.
• Check for Mesh Instance - Indicates whether the mesh should be checked against other meshes to determine if it is in instance. This setting is ignored if the object is a Submesh or the Check for Mesh Instances setting of the scene mesh settings is disabled.

Normal/Tangent/Binormal Settings

• Generate Normals - Indicates whether normals should be generated and exported.
• Animated Normals - Indicates whether animated normals should be exported for mesh pose and morph animations. Note that this feature is only available in Ogre 1.8 and above, and is incompatible with stencil shadows.
• Generate Tangents - Indicates whether tangents should be generated and exported.
• Binormals - Indicates whether binormals should be generated and exported.
• Split Mirrored - Indicates whether to split vertices when a mirrored tangent space transition is detected.
• Split Rotated - Indicates whether to split vertices when tangent space rotates more than 90 degrees around a vertex.
• Store Parity In W - Indicates whether tangent space parity should be set in the W of a 4-component tangent.