@b0rk
Yes, but you're operating at a level higher than that. You're looking at ASCIIDOC that has been converted into some macro-set, that then becomes roff (or is interpreted directly in some cases). I'm guessing asciidoctor.
asciidoctor appears, from a quick shufti of the source, to generate output that targets the "an" macro set rather than the "doc" macro set. For the particular page you've mentioned it is generating conditional code that either directly moves the horizontal position with \h, or uses the .IP macro to make an indented paragraph with a hanging bullet.
https://github.com/asciidoctor/asciidoctor/blob/main/lib/asciidoctor/converter/manpage.rb#L496
In both cases, the indent is directly hardwired into the asciidoctor source. As you can see, it moves -4 ens right (i.e. 4 ens left) and 3 ens back with \h, and in the alternative fork gives the .IP macro the indent setting 2.3.
https://oreilly.com/openbook/utp/
https://cmd.inp.nsk.su/old/cmd2/manuals/unix/UNIX_Unleashed/ch09.htm
My educated guess is that -4 and 2.3, unchanged since 2015, were copied from some other tool.
#man #asciidoc