Typo in Chapter 15 (version 1.1 of the data format spec) or Chapter 20 (version 1.3)
I believe the second anchor sub 3,2 reference in the first NS=3 case should be 3,3.
There's another typo at least in version 1.1 in table 15.3. Mode 5, G sub 1 is bits 29...34, but that's only six bits instead of seven; it should be 29..35; B sub 0 is wrong, it should be 36...42, B sub 1 should be 43...49, after which it's correct again.
Oops, well caught. Thank you, will attempt to update soon.
Fixed in 1.4.0. 1.1 is deprecated, although I think it might still be referred to by GL and GLES. Leaving this issue open until determining whether to revise GL and GL to update to 1.4, or whether to try to backport this (and other fixes).