The naming of UV sets in the official documentation is inconsistant, missleading, incorrect and incomplete. I would propose the following changes. Based on the information provided by Unity employees in the thread http://forum.unity3d.com/threads/quick-setup-for-starting-enlighten.309609/#post-2400531. 1) In the Mesh page page http://docs.unity3d.com/ScriptReference/Mesh.html. Mention that UV2 is used for realtime lightmapping but NOT baked lightmapping so don't try to use it for anything else if using any GI. Mention that UV1 exists but it is not readable nor writable and that it is used for baked lightmapping. This is very important information. The API says that this channel is depricated which suggests it is not used anymore and does not exist. It does exist and is used for baked lightmaps. Without this information a developer could literally spend weeks trying to work with UV2 and baked lightmaps and have not idea why nothing is working. The docs say that UV2 is the "second" UV set. This is not correct. It is the "third" UV set. The existing language suggests that there is no UV1 which leads developers to a false assumption and weeks of lost development time. Please NEVER refer to to uvs as "first", "second", "third" etc.. Please ALWAYS use uv, uv1, uv2, uv3, uv4. 2) Unrwapping.GenerateSecondaryUV set does this generate a UV1 channel? I think it must because I can create baked lightmaps on procedural meshes after I call this. Please mention this. 3) Renderer page please mention that Renderer.lightmapScaleOffset uses the UV1 channel. I have been wondering for months what mysterious set of lightmap UVs these correspond to. Also mention that Renderer.realtimeLightmapScaleOffset uses the UV2 channel. 3) In the manual please mention that Unity uses different UV sets for realtime GI and baked GI. Please include the information in this document https://goo.gl/bHsCyq in the manual. There is not enough detail about GI in the regular manual. This is the best information on GI in unity I have seen so far and would have saved me weeks of development time. The inspector for the standard shader uses: Please name the UV sets correctly as UV3 and UV4. If a developer interprets the names in the inspector literally then they will waste many hours of development time.