# [dev-context] context commands in lua-files

Peter Münster pmlists at free.fr
Sun Jul 18 09:46:58 CEST 2010

```On Sun, Jul 18 2010, Peter Münster wrote:

> > - If all the three arguments are optional, it's a bit difficult to
> > tell what combination of arguments is allowed, so it might make sense
> > to be a bit more verbose in that (to tell somehow that for example
> > only 123 and 23 and 3 is allowed, but not 13 for example), but this is
> > not too important.
>
> I think, there has to be some introduction chapter for the user with the
> general rules in ConTeXt-commands. I suppose these rules:
> [...]

And when a command does not follow these rules (perhaps \externalfigure is