Most Common Use of Nulls in 15th Century Cipher Text

[MichelleL11]

Here are the assumptions -- that are admittedly far, far from having proof to support them:

1) The VM is a ciphered text, with an actual, widespread natural language plaintext underlying it
2) Every use of EVA "y" within the text is a null (that is, that glyph has has no underlying corresponding character (or characters) in the plaintext that it is represented by) -- basically, someone who is decoding the VM message should IGNORE that character

Given these two assumptions, I wanted to examine Koen's work on removing EVA y (after the bigram alterations).  The result he found was that entropy is signficantly increased (e.g. there is significantly more disorder).

Now if we use the traditional definition of a null -- that is, that symbol in the cipher "does not care what other symbols it sits next to" it is clear that EVA "y" is not behaving how a traditional null is defined.  

I was wondering about the traditional use of nulls at the time of the VM carbon dating.

Does anyone have any insight into the use of nulls in 15th Century ciphers?  That is, are we getting "anachronistic" with some sort of non-traditional null.  By non-traditional null I mean, after every symbol (or pair of symbols) that stand for plaintext letter X, add a null, rather than "random" scattering.

I am finding it hard to imagine the motivation for a"non-traditional" null other than in relation to confounding some sort of frequency analysis, which I understand is a further anachronism.  But if someone can come up with an alternative, I would be very interested in hearing about it.

Well -- I guess I have now answered my own question, as I suppose it could be hypothesized that nulls do not occur at the glyph level, but instead at the whole word level -- and if those null words were highly ordered, removal of a portion (like the "y"s only) could have this effect on entropy, even if the nulls were actually used in a "traditional" sense, as defined above.

In any case, would be interested in any other thoughts along these lines or just some comment on how varied the use of nulls were at the time and thanks for thinking about it!