help: show "[no-]" only for default-on Flags As Anton (av6) pointed out, the "[no-]" is confusing for action flags like `hg bookmark --delete`. We could come up with a way of indicating which flags are action flags (e.g. use None for the default value instead of False). However, it's probably also unlikely that users will want to negate even non-action flags like --hidden. One of the more common flags where the "[no-]" prefix would be useful is `hg evolve --update`. The reason it's helpful there is that it defaults to on. So I think we can simply include "[no-]" only for flags that are on by default (and thus require the user to add the "[no-]" for the option to have any effect). Note that there are use cases for negating flags that already off by default. For example, you may have an alias for `hg log -G --hidden -T foo` and now want to pass "--no-hidden" to that alias. However, I think that users who want that are likely to be advanced enough that they've already learnt about the "no-" prefix by seeing it somewhere else. Differential Revision: https://phab.mercurial-scm.org/D5454