On plain texts and ciphers (a thought experiment)

[Sam G]

By the by, I do personally think that initial [q] and final [l] are likely to be morphological markers. I just can't prove it. I don't think we're at the point where we can understand the text and underlying language well enough.

I think the fact that q is almost totally absent from the labels points toward it being a morphological marker of some kind - you don't need it to label individual items, but you do need it to write complete sentences.