Allow like grep -B: Show lines before a match

[jidanni]

In Less 551,

       n      Repeat  previous  search, for N-th line containing the last pat‐
              tern.  If the previous search was modified by ^N, the search  is
              made  for the N-th line NOT containing the pattern.  If the pre‐
              vious search was modified by ^E, the  search  continues  in  the
              next  (or  previous)  file if not satisfied in the current file.
              If the previous search was modified by ^R, the  search  is  done
              without  using  regular  expressions.  There is no effect if the
              previous search was modified by ^F or ^K.

is great, except that it always puts the matched line at the top of the
screen. Let's say we are looking at
$ less +/longlat/ epsg.txt

# Unknown datum based upon the Bessel Namibia ellipsoid
<4006> +proj=longlat +ellps=bess_nam +no_defs  <>
# Unknown datum based upon the Clarke 1858 ellipsoid
<4007> +proj=longlat +a=6378293.645208759 +b=6356617.987679838 +no_defs  <>
# Unknown datum based upon the Clarke 1866 ellipsoid
<4008> +proj=longlat +ellps=clrk66 +no_defs  <>
# Unknown datum based upon the Clarke 1866 Michigan ellipsoid
<4009> +proj=longlat +a=6378450.047548896 +b=6356826.621488444 +no_defs  <>
...

Well we need a CLI parameter to always show us one line above the match,
so we can read the comment that belongs to the match.

[gwsw]

Doesn't the -j option do what you are asking for?

[jidanni]

By the way, maybe mention on the man page that "...thus -j 0 and -j 1 are no-ops.
The real action begins at -j 2."