This is not really about documentation but about an error in the opkg command. I hope it fits here as well.
:~$ | => opkg | grep regexp
opkg must have one sub-command argument
remove <pkgs|regexp> Remove package(s)
search <file|regexp> List package providing <file>
find <regexp> List packages whose name or description matches <regexp>
info [pkg|regexp] Display all info for <pkg>
status [pkg|regexp] Display all status for <pkg>
regexp could be something like 'pkgname*' '*file*' or similar
e.g. opkg info 'libstd*' or opkg search '*libop*' or opkg remove 'libncur*'
(last line copied afterwards by me)
I know in the last two lines it explains what a regexp is. But this is not what everyone understands by that. This is clearly a globbing pattern. How can I find out who maintains this package? I like to suggest replacing the word <regexp> with wildcard or something similar.
Yes, writing this costs me more time than I needed to figure out why my regexp didn't work. Usually you read the single line you need (e.g. find) and move on.
I hope my suggestion will improve opkg, even if it's just a little bit.