Updating legal section
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### Legal/IP/license stuff
-Basis Universal uses texture compression formats or technologies created by several companies: ARM Holdings, AMD, Ericsson, Microsoft, and Imagination Technologies Limited. All are supported by various open standards or API's from [The Khronos Group](https://www.khronos.org/), such as OpenGL 4.5, OpenGL ES, or Vulkan.
+Basis Universal uses texture compression formats or technologies created by several companies: ARM Holdings, AMD, Ericsson, Microsoft, and Imagination Technologies Limited. All are supported by various open standards or API's from [The Khronos Group](https://www.khronos.org/), such as OpenGL 4.5, OpenGL ES, or Vulkan.
+
+A few texture formats (such as AMD/ATI's ATC texture format, or PVRTC2) were not documented sufficiently by the originator of the format. In these cases, we relied on open source code references from other authors, or information in published articles/papers to implement support for those texture formats in our transcoder. These references are included here.
ASTC usage follows ARM's [END USER LICENCE AGREEMENT FOR THE MALI ASTC SPECIFICATION AND SOFTWARE CODEC license agreement](https://github.com/ARM-software/astc-encoder/blob/master/LICENSE.md). Note the ASTC texture format is the only standard we could identify that is covered by an explicit end user license, and we believe our use case is covered by this license.
-PVRTC1/2: See the [PVRTC Specification and User Guide](https://www.imgtec.com/downloads/download-info/pvrtc-texture-compression-user-guide-2/). Imagination Technologies Limited, 23 Nov 2018. Also see the [Khronos Data Format Specification](https://www.khronos.org/registry/DataFormat/specs/1.1/dataformat.1.1.html). See [PVR Texture Compression Exploration](https://roartindon.blogspot.com/2014/08/pvr-texture-compression-exploration.html) and [PvrTcCompressor](https://bitbucket.org/jthlim/pvrtccompressor/src) Also see (Texture Compression Techniques)[http://sv-journal.org/2014-1/06/en/index.php?lang=en#7-3]
+PVRTC1/2: See the [PVRTC Specification and User Guide](https://www.imgtec.com/downloads/download-info/pvrtc-texture-compression-user-guide-2/). Imagination Technologies Limited, 23 Nov 2018. Also see the [Khronos Data Format Specification](https://www.khronos.org/registry/DataFormat/specs/1.1/dataformat.1.1.html). See [PVR Texture Compression Exploration](https://roartindon.blogspot.com/2014/08/pvr-texture-compression-exploration.html) and [PvrTcCompressor](https://bitbucket.org/jthlim/pvrtccompressor/src) Also see [Texture Compression Techniques](http://sv-journal.org/2014-1/06/en/index.php?lang=en#7-3)
ETC1 and ETC2 EAC: See the [Khronos Data Format Specification](https://www.khronos.org/registry/DataFormat/specs/1.1/dataformat.1.1.html) and the [OpenGL 4.5 Core Profile](https://www.khronos.org/registry/OpenGL/specs/gl/glspec45.core.pdf) Appendix C.
