[GRASS-dev] doubt with single/double dashed flags from interface description

[andrea antonello]

Hi all,
I have a problem with the handling of flags in the interface description.

Let's take for example pieces of r.watershed,
The help tells me:
[...]
  -a   Use positive flow accumulation even for likely underestimates
        See manual for a detailed description of flow accumulation output
 --o   Allow output files to overwrite existing files
[...]

and the interface description:
[...]

	<flag name="a">
		<label>
			Use positive flow accumulation even for likely underestimates
		</label>
		<description>
			See manual for a detailed description of flow accumulation output
		</description>
	</flag>
	<flag name="overwrite">
		<description>
			Allow output files to overwrite existing files
		</description>
	</flag>
[...]

I can't find a way to understand why the first has one single dash,
while the overwrite flag needs two.
Any hints?

Thanks,
Andrea