Can lowlighting less important text improve readability? Are there alternatives? I think many experience the following: Sometimes I want to get the main message of a paper within 10 min then I am annoyed by any less important details distracting me. And sometimes I spend days or weeks to understand a certain part of a paper, where I would highly appreciate any further information on that aspect of the paper. Or I am just very curious if the authors got further results on a very specific aspect of their paper.

So I think good papers should be more interactive in a way that the reader can easily choose which parts to read and which parts can be skipped without missing the main message (or the introduction of the notation necessary to understand the main message).

I know about the following methods to achieve this goal:


less important stuff in the Appendix
Using remark environments to indicate that a certain remark provides additional information.
Using good section titels to let the reader choose which aspects they want to read.
Using footnotes to provide optional additional information that is specifically related to the content at the position where the footnote appears
Using lowlighted (i.e. grey / half transparent) text to indicate less important additional optional information.
Using smaller fontsize to indicate less important additional optional sections or paragrahps.
\underbrace, \overbrace to explain certain terms (that might be obvious to some readers)
\overset such as $a\overset{\text{Th. 1}}{=}b+c$ to indicate that a=b+c holds true because of Theorem 1, which might be obvious to some readers, but not to others.
(Writing something unimportant in parenthesis.)
There are probably more options...


I think all of these methods have their advantages and disadvantages and I think for each of them there exist scenarios where they can be very helpful for readability. I don't really understand why some journals and even Arxiv forbid some of them.

Question 1: What are the pros and cons of low lighting text by making it half transparent? Are there situations where it is helpful?

I think for example for papers in the intersection of mathematics and computer science grey symbols inside formulas can be useful to allow readability for both communities. E.g. a real valued random variable X is typically introduced as $X:(\Omega,\Sigma)\to(\R,\mathfrac{B})$ in mathematics literature, but this might unnecessarily confuse some computer scientists, because in this field of computer science the assumptions expressed by this notation are typically made implicitly without explicitly writing it down. So making :(\Omega,\Sigma)\to(\R,\mathfrac{B}) half transparent is understandable for both communities.

Therefore, we wrote our paper using lots of lowlighting and uploaded it to Arxiv a couple of months ago. Now, we wanted to update it fixing some typos and to furhter generalize the theory, but we got a mail, that highlighting and lowlighting is not accepted by Arxiv, because it is too unconventional.

Question 2: What can we do know? Is there an equally good alternative instead of lowlighting?

Related other questions:
Is there a way to improve the readability of equations in research papers?
Is highlighting important references a good idea?
Yes, there is an alternative to de-emphasizing the less important parts (which might possibly impair readability): Emphasize the most important parts. Something you can do is to use clearly outlined boxes with "take-home" messages, like in the example below: