Rohoncian looks like a case-marking language with prepositions

The computer-assisted transcription of the Rohonc codex is about 61% done. So far, I'm resisting the urge to do any kind of statistical analysis because the results will almost certainly be skewed by the fact that my glyph recognition algorithm has a harder time with some glyphs than others.

However, I came across something today that I thought was interesting. Throughout the codex, there is a sequence of four glyphs that is usually written with a halo over it, as follows:

Co D Co D

Starting from this post, I'll use my provisional transcription system, so I don't have to talk about "the glyph that looks like a triangle", and so forth.  So this sequence is transcribed as Co D Co D.

I think the odds are good that this is a noun, or a proper noun, but of course it is not clear what it is. It could be an epithet of God, the Holy Spirit, or even an abstract noun like Grace, but for the sake of convenience I'll call it "the holy noun". At first blush, it looks like a reduplicated stem, but there are a few cases where it appears to be inflected.

In an earlier post, I suggested that the simple line bending to the left was a preposition line "on". I now transcribe this glyph as L (for "left"), and in the following sequence you can see two cases where the holy noun is preceded by L, and at the same time the ending of the sequence changes:

L C D C I Ix Hk L C D C I

It may or may not be important, but in this case the glyph Co is replaced by C. But since the only difference between the two is a small loop at the top, it is possible that they are allographs of the same grapheme.

More important is the suffix. It looks like the (tentatively) nominative suffix D becomes I when the noun is prefixed by the preposition L.

Compare also the following:

O Co D C D C

It seems fairly clear that this is the same holy noun (marked with a halo, as always), but it has an added C suffix after the D. This may or may not be related to the O that precedes the whole word.

If these sequences really do show prepositions and case-marking, then it narrows the field of candidate languages quite a bit. We would be looking for a language with prepositions and at least three cases. Here is the rough paradigm of a noun in -D:

Possible Nominative: stem + D
Oblique A: stem + I
Oblique B: stem + D C