[maemo-users] Is it correct to use SDK repos for installing packages onto the device?

[From: James Brown]

When I try install mutt http://maemo.org/packages/view/mutt/ I have the
next result:
> sudo apt-get install mutt
> Reading package lists... Done
> Building dependency tree       
> Reading state information... Done
> Some packages could not be installed. This may mean that you have
> requested an impossible situation or if you are using the unstable
> distribution that some required packages have not yet been created
> or been moved out of Incoming.
> The following information may help to resolve the situation:
> 
> The following packages have unmet dependencies:
>   mutt: Depends: slang1a-utf8 (> 1.4.9dbs-4) but it is not installable
> E: Broken packages

Here
http://maemo.org/packages/package_instance/view/fremantle_extras-devel_free_i386/mutt/1.5.20-3/
I can read that I need add into my sources.list the SDK repo: deb
http://repository.maemo.org/ fremantle/sdk free non-free (or install
that package for SDK from here: http://maemo.org/packages/view/slang1a-utf8/
Is it correct way to install packages using SDK repos for device?