Punctuation marks: The Metas

Not once would I have suspected that I might be addressing this topic in writing, so this is just as much of a challenge for me to write as it will be for you to read.
Why so? Because it means the main deliverance here will be that of confusion and question marks, rather than precise thoughts or rants and secondly, because it means wording against my prevalent obsession with [almost-] perfectly rounded up ideas, rather than stubs.
It is, on the other hand, an expression of my [other] obsession[s] with hoarding, which needn't address reality-defined items alone, as you're about to witness :)

So here are the 2 finds:
The first is the Wiki entry to the so-called Irony mark, 'also called a snark or zing': this has been very recently brought to the public's attention by my beloved sister. An interesting find, I think, and even more so due to its more-than-limited application:

This mark ؟ was proposed by the French poet Alcanter de Brahm (alias Marcel Bernhardt) at the end of the 19th century. It was in turn taken by Hervé Bazin in his book Plumons l’Oiseau (1966), in which the author proposes several other innovative punctuation marks, such as the doubt point, certitude point, acclamation point, authority point, indignation point, and love point.
Its form is essentially the same as the late medieval Irony mark, a percontation point (punctus percontativus), which was used to mark rhetorical questions.

So why - ask I - has the percontation point seen such a short lived usage? Is it the desire to leave irony to the whim of the reader to be blamed here? Or is it rather the unwillingness of the writer/s to convey meta in general? I'm baffled, and the first reason why is because this is the first time I encounter the percontation point being mentioned at all. Ideas?
Later edit: Or it could be just a matter of timing, if I were to consider the late 20th century/ beginning of the 21st century advent of the Emoticons subculture.. right?

The second is way easier and yet more difficult for this very reason: it's about the conventional use of square brackets, other than their mathematical, computer science or natural sciences ones [read: not-formal sciences].
Here's what puzzled me: Other than the visible common-knowledge uses one can read up in the Wiki entry I've pasted above, I've recently learnt of the meta of square brackets in corporate language - delivered to me in a very friendly email. The comment says: 'square brackets are commonly used in our [company/ work environment] to refer to information which hadn't as yet been confirmed or which might be deleted - but they should never be seen in a final document'.
This was new to me, really new in fact. New enough so that I get to ask: Is it just me that remained blinded in front of this remarkable connotation? How come I had never been told anything on this matter? Or is it a corporate thing?

Let me know if you have answers [general knowledge, or otherwise]: the Metas of punctuation marks have all of a sudden become an overwhelmingly hot topic!